NKA Rules - National Karting Alliance

Transcription

Introduction and Scope
The National Karting Alliance
The NKA (National Karting Alliance) was formed in 1985 to promote the sport of kart
racing, with a specific goal of providing tools and assistance to the US karting facility.
Over the years, the NKA has grown to offer its unique services to almost 400 facilities,
series, and events comprised of all types of karting, and from across the entire US.
We believe that the facility, and the economic infrastructure that surrounds each facility,
are the lifeblood of the sport of karting. Our mission is to actively engage the facilities,
industry, and their customers to ignite the economic engine of karting.
What is TrakBOOK?
TrakBOOK is the first set of rules written by a major organization to be developed
from the perspective of the facility, series, or event and not the organization. This
allows those facilities to use TrakBOOK as their foundation, while at the same time
allowing them to make minor changes that are necessary for their individual program
through the Supplemental Rules section of TrakBOOK. In this way, our facilities have
autonomy over their specific needs, while the sport heads in the same general direction
with TrakBOOK as the foundation.
TrakBOOK is not intended to be revolutionary. TrakBOOK is simply a set of rules
that allow the facility, series, or event to manage, officiate, and determine technical
compliance for an event. Too often it seems that rules are used for purposes outside
of their initial intent, and we don’t feel that this is the right path for our sport to grow
and prosper.
TrakBOOK is intended for the use of specifically authorized NKA Member Facilities, or
NKA Affiliated Facilities.
• A Member Facility has joined the NKA by application and membership dues, utilizes
TrakPASS, has access to other benefits of the NKA, and is encouraged to participate
in the evolution and growth of TrakBOOK.
• A NKA Affiliated Facility must only register with the NKA and provide proof of
insurance from an authorized and recognized source. If you are not willing to make
sure that your business and racers are properly cared for, then we do not see a good
reason to provide TrakBOOK to you. Please contact the NKA at info@nkaonline.com
to request information regarding compliance.
If you are an NKA Member Facility, we invite you to be a part of the management
process of TrakBOOK. Please let us know via info@nkaonline.com if you are interested
in being involved in one of our TrakBOOK Management Groups.
Table of Contents
SECTION 1: General Regulations
Page 3
SECTION 2: Licensee & Competitor Categories
Page 4
SECTION 3: Officials Duties
Page 6
SECTION 4: Safety
Page 8
SECTION 5: On Premise Regulations
Page 13
SECTION 6: Protests & Appeals
Page 18
SECTION 7: Sprint Racing Kart
Page 20
SECTION 8: Speedway Racing Kart
Page 30
SECTION 9: Road Race/Enduro Racing Kart
Page 38
SECTION 10: 100cc or less 2-Cycle Engines
Page 47
SECTION 11: 125cc “TAG” Engines
Page 64
SECTION 12: 125cc Spec Honda Engines
Page 70
SECTION 13: Honda GX-50 Kid Kart Engine
Page 73
SECTION 14: Briggs 5HP “Flathead” Engine Page 76
SECTION 15: Stock OHV 200 Engine
Page 79
SECTION 16: Briggs Animal Engine
Page 85
SECTION 17: Briggs LO206 Engine
Page 90
TECH LEVELS
Page 106
Section 1: General Regulations
1.1 General:
TrakBOOK was created to provide a manual for the operation of karting at all levels from local
tracks through national events.
1.1.1 All members, drivers, pit crew, and participants in general should be fully versed with the
all applicable sections of TrakBOOK, as well as any other specified rules and regulations that
are part of any event.
1.1.2 It is the responsibility of every driver, owner, or crew member to prepare and operate his
or her racing kart in a safe manner at all times, under all circumstances.
1.1.3 It is the responsibility of the track owner or operator to provide a track as safe as
reasonably possible for the competition events to be run.
1.1.4 TrakBOOK is a living document and can be modified, added to, or subtracted from for
each individual track/series/event, as needed and with the assistance of the NKA Technical
Department. TrakBOOK is written with the benefit of the local track owner, kart racer, and the
best intentions of the sport of karting in mind.
1.1.5 Drivers will at all times be responsible for their own conduct and the conduct of their
crews. Any offense committed by a crew member may be chargeable directly to the driver. This
particularly applies during the running of an event while the driver is away from their pit. The
responsibility may also extend to conduct in the local area of an event, including motels, hotels,
restaurants or any private or public area.
1.1.6 NKA Member Facilities and/or their respective Race Directors reserve the right to refuse
any entry or rebuke any racing/pit license for conduct that does not represent karting in a
positive light (foul language, arrests, public intoxication, substance abuse, or other immoral,
unethical actions).
1.2 Spirit and Intent
All rules within TrakBOOK are written with the concept of Spirit and Intent in mind. The goal of
each facility, and its technical department, should be to provide a consistent arena for the sport
of karting to occur.
Spirit and Intent establishes that these rules are provided as a manual to follow to assist facilities,
series, and events in the production of effective karting events.
Therefore, it should not be the goal of the racer to “read between the lines” to manipulate the
rules for their advantage. Conversely, it should not be the goal of the facility to look for ways to
disqualify a racer. We’ve all heard of the racer disqualified for the tiniest of infractions, and that
is not the purpose of our sport, or TrakBOOK.
At all times, we encourage the facilities and their racers to keep the concept of Spirit and Intent
in mind.
1.3 Dangerous Conditions
The event officials have the right to stop, postpone, or cancel any event if they deem conditions to
be dangerous. This includes weather, track conditions, driver(s) actions, or any other condition
that may arise and threaten the safety or well being of competitors, spectators, officials, or other
people at or near the event.
1.3.1 Lightning: If lightning is observed in the area of the racing facility, immediately cease all
on-track and outdoor activities or be advised to seek their own shelter should a common indoor
area not be available. All participants and spectators should be moved indoors. Competition
can resume 30 minutes after the last sighting of lightning is observed.
1.4 Supplemental Rules/Local Option
1.4.1 Individual tracks, events, and/or series have the right to add “Supplemental Rules”.
Supplemental Rules may take precedence over TrakBOOK and must be published and
accessible to all competitors at least ten (10) days in advance of the event.
1.4.2 Section 1.4 is intended to allow each facility to regulate its own general operations, class
structure, technical specifications (to supplement a class/engine not contained in TrakBOOK),
weights, etc. Areas involving safety, either intended or unintended, may not be minimized in
scope.
1.4.3 Local/event Race Directors have the right to add Supplemental Rules as conditions
dictate. The Race Director must make every effort to communicate the Supplemental Rules
as quickly and effectively as possible via the track’s public address system, a competitors’
meeting, printed handout to competitors, and/or other means at the Race Director’s disposal.
1.5 Legal Action: Any competitor, or Parent or Legal Guardian of the competitor, that threatens
legal action via an attorney, or files legal action against the NKA or NKA Member Facility, or any
of its legal agents or staff, will be permanently banned from that facility as well as any other NKA
Member Facility.
1.6 Disclaimer: TrakBOOK offers no warranty, expressed or implied, resulting from the
compliance of these rules and regulations that govern karting events. Racing is a dangerous
sport that can result in injury, dismemberment, and even death. No rules or regulations can
guarantee the elimination of those risks. Your (or your child’s) participation in the sport of karting
is at your own risk.
1.7 Insufficient Funds or Reversal of Credit Card Fees:
may result in probation, suspension, termination of membership, or legal action. If an entrant
has insufficient funds, the entrant has ten (10) days from the start of the event to rectify the funds
or they will automatically forfeit all rights and privileges from the event.
Section 2: Licensee and Competitor Categories
2.1 Competitor in Good Standing
Any driver or minor driver’s supervising parent/guardian must be in good standing with the
facility, event, or series to be eligible to compete at any NKA Member Facility, event, or series.
Reasons, including but not limited to, that a driver would not be in good standing: (1) suspension
for assaulting (verbally or physically) an official, another competitor, or spectator (2) reckless
driving on track (3) a positive drug or alcohol test, or other reasons not listed here.
The TrakBOOK Competition Committee (TCC) is available to mediate or facilitate proceedings
between a Member Facility and any competitor. Additional fees may be required depending on
the issue. If the TCC is engaged to mediate a dispute, their decision must be final.
2.2 General NKA License
Not required for the 2014 racing season by the NKA.
2.3 Competition License
Not required for the 2014 racing season by the NKA, may be required by specific series or event.
2.4 Competition Pro License
Not required for the 2014 racing season by the NKA, may be required by specific series or event.
2.5 Technical Inspector Endorsement to General License
Required by certain NKA sanctioned tracks and/or series. Can be waived at the discretion of the
race promoter or if person has technical inspection accreditations from other sanctioning bodies.
2.6 Temporary Competitor License
A temporary competitor license may be required by an NKA Member Facility. This information
should be supplied to you via that club, track or series. Contact the NKA Member Facility for
more information.
2.7 WAIVER REQUIREMENTS
2.7.1 RELEASE AND WAIVER OF LIABILITY, ASSUMPTION OF RISK, INDEMNITY
AGREEMENT: All persons who intend to enter a restricted area (thereby becoming a participant
of that event) shall sign the official Release and Waiver of Liability, Assumption of Risk, and
Indemnity Agreement provided to the facility by the NKA before being allowed to participate
in any event at a NKA member track. All participants, by signing the waiver, hereby elect to
use the track at their own risk, and thereby release and forever discharge NKA, Inc., together
with their heirs, assigns, officers, representatives, agents, employees and members, from all
liability from injury to person, property, employees and/or reputation, that may be received by
said entrant and/or driver, and from all claims of said injuries to parties listed above growing
out of, or as resulting from the event contemplated under the entry form, or caused by any
construction or condition of the course over which the event is held.
2.7.2 PARENTAL CONSENT RELEASE AND WAIVER: It is mandatory that at least one parent
or legal guardian of a minor 17 years old or younger fully execute the Parental Consent and
Release and Waiver of Liability, Assumption of Risk, and Indemnity Agreement before being
allowed to participate on any NKA member track unless there is a copy on file at the NKA
administration office. The NKA MINOR REPORT is to be signed by a parent or legal guardian.
2.8 COMPETITION AGE: A driver’s actual age as of JUNE 1 of each year shall establish their
“competition age” for that calendar year. For example; a driver is 9 years old on April 1, but he/
she turns 10 in May. The drivers “competition age” for that year is 10, which is their age on June
the first.
2.9 OPTION YEAR: The NKA allows for the +1/-1 age option. A driver in good standing is
allowed to add one year to their competition age, or subtract one year from their competition
age to be able to compete in a class that closer fits their skill level and ability that is normal and
acceptable.
For example; a driver’s competition age for the year is 11. Their skill level and ability is better
served in a class that requires a minimum of 12 years old. The driver is allowed to add one year
(+1) to their “competition age” and can compete in the class.
Once a driver has moved up in age, and has competed one full event at the higher level, they
must decide whether to remain at that level or revert back to the lower division.
The track or club has the right to approve or not approve any +1/-1, for any reason that they feel
is prudent. The NKA will not overrule this judgment.
2.9.1 Proof of Age: any driver may be required to prove his/her age at any time during an event
via one or more legal documents such as birth certificate, driver’s license, passport, etc.
2.10 General Health: Pregnant women are not allowed to participate as a driver at any NKA
event. In addition, it is expected that all participants deem themselves as healthy and able to
compete. It is not the duty of the facility to determine health of the participant.
2.11 Legal Entrant: A driver is not allowed to participate at a sanctioned event unless he is a
legal entrant in said event. Driver must be entered in a class before being allowed to participate
in practice.
2.11.1 Relief Driver: Not allowed unless a “unique” situation arises and is approved by the Race
Director.
SECTION 3: OFFICIALS DUTIES
All officials in their assigned duties must be familiar with all rules and regulations, which apply
to those duties.
3.1 OFFICIALS POWERS: The designated officials of any NKA Member Facility event shall
have the power of rule enforcement and race supervision. Any Official at an NKA event can
report a dangerous driving situation or other rules violation that is observed on-track. The
decision on whether to issue a penalty or not lies with the Race Director.
3.2 RACE DIRECTOR’S DUTIES: The Race Director shall be that official having complete
charge of all officials, technical inspector, turn marshals, the track, and karts during all “official
times” the event is occurring. The Race Director shall disqualify (through signals to the starter)
any driver who, in their opinion or that of their observers, is in violation of the rules or whose kart
is or has become unsafe to operate. The Race Director, or their designated representative, shall
uphold all rules and regulations.
3.2.1 Assistant Race Director: Larger events and/or tracks might necessitate the need for an
Assistant Race Director position. This person works directly with the Race Director and serves
as “a second set of eyes and ears” for the Race Director. It is the decision of the Race Director
to allow the Assistant Race Director to make on-track “calls” such as a black-flag or warnings.
3.3 FLAGMAN’S DUTIES: The Flagman shall be that official having complete charge of the
flags. The Flagman shall follow instructions from the Race Director. The Flagman’s flag signals
are to be obeyed without exception. If necessary, the Flagman shall conduct a meeting for all
drivers prior to the start of the event to explain the flags, their use, and rules of the road.
3.4 CHIEF SCORER’S DUTIES: The Chief Scorer shall be that official in charge of timing and /
or scoring. The Chief Scorer shall keep the Flagman informed of positions, laps completed, etc.
Each entrant’s kart shall be assigned an identifying number, which will be carried at all times
during the event. The number shall be of sufficient size and color as to promote scoring. The
entrant shall accept the assigned number and affix these numbers to their kart in a manner
acceptable to the Chief Scorer.
3.5 TURN MARSHAL’S OR FLAG DUTIES: Flag Personnel shall be strategically located
around the course to use the yellow flag when necessary to signal drivers as to accidents,
debris, fluid or other hazards on their portion of the track. Flag Personnel shall also report any
rule infractions to the Race Director.
It is not the duty of a turn marshal to assist drivers at the scene of the accident or incident to get
their karts separated or going again. Their duty is to warn oncoming traffic of an incident, and to
direct race control of the possible need of additional resources if necessary.
3.6 PIT STEWARD’S DUTIES: The Pit Steward shall be that official(s) having charge of the pit
area. The Pit Steward shall keep all unauthorized persons out of the area, assign the pit spaces,
grid the next class, and report any irregularities or rule infractions to the Race Director.
3.7 TECHNICAL INSPECTOR DUTIES: The Technical Inspector shall be that official(s) having
charge of the pre and post race inspection. The Technical Inspector shall designate an area
where karts and drivers will be checked for minimum class weight, maximum kart size, engine
legality, exhaust system legality, legal attachment of weights, fuel legality, etc.
Entrants are responsible to the Technical Inspector while in the impound area and are subject to
disqualification if they leave without the Technical Inspector’s approval.
The Technical Inspector has the final say over any and all tech inspection questions. The
Technical Inspector has the authority to retain any part judged to be out of technical compliance;
however, the part must be returned at the conclusion of the event unless submitted to the
TrakBOOK Competition Committee for further review (see section 6.3.2 for more information).
A technical inspector can call the NKA Technical Director for clarification on any rule; if further
clarification is needed.
SECTION 4: SAFETY
Safety is the prime consideration of NKA. Methods of operation, vehicle construction, track
facilities and competition practices are under constant review to protect the karter, crew, and
spectators also to raise the safety standards of the sport. Unless specified otherwise, these
safety regulations are considered mandatory and may not be superseded by any Supplemental
Rule, or Local Option rule.
In addition, this section should be considered the minimum, not maximum. It is not reasonable
to expect that the TrakBOOK program be able to fit and regulate any and all situations regarding
safety. It is the opinion of the NKA that the safety of everyone includes diligence by the facility,
staff, volunteers, competitors, and associated industry or retail representatives. Our sport
depends on the long term recognition that safety is not just a buzzword, but a responsibility that
we must all assume to ensure the safety of everyone.
4.1 PROHIBITED SUBSTANCE: All participants entering the restricted area (pits) of a NKA
event shall be sober and not under the influence of any substance that may impair their ability
to participate in a safe and orderly manner. It is the responsibility of the participant to withdraw
from competition if they are taking medication that may display side effects that would impair
their ability to safely compete. If, in the judgment of the officials in charge, an individual is under
the influence of alcohol or any controlled substance during the period of an event, they may be
ejected from the restricted area and/or event site immediately.
4.2 EXCESS MEDICAL INSURANCE: All participants at any NKA Member Facility have access
to the NKA Excess Medical program that is part of our TrakPASS product. The amount may vary
by the facility.
Access to this is not a replacement for a major medical health insurance plan. It is highly
recommended that you have proper health insurance if you choose to compete, or be around in
any way, competitive racing or general on track activities.
4.3 ACCIDENTS: Karts involved in an accident may be required to stop for inspection by the
officials. Accidents shall be investigated by the track officials only. No pit personnel are permitted
on the track while the race is in progress.
4.4 ACCIDENT REPORTS: A NKA accident report must be filed by an NKA member facility
any time an injury occurs during the conducting of an event; refer to TrakPASS guidelines for
instructions on completing accident report.
4.5 EMERGENCY EQUIPMENT: It is mandatory that there be the basic First Aid medical
equipment on site during any official event.
4.6 FIRE EXTINGUISHER: It is highly recommended that each entrant in the event have a
minimum of one operable 1-1/2 pound dry-powder fire extinguisher (rated for use on A, B, &
C. type fires) in their pit area. It is recommended that they have one on the starting grid at the
start of each race in the hot pit area. Carbon Dioxide type extinguishers are not acceptable
substitutes for the dry-powder type.
4.7 TRACK ACCESS: During “live/hot” sessions, no person or race official shall be permitted
on the racing surface at any time.
4.7.1 Multiple plastic barriers, tires, or hay bales should be provided at corners for the protection
of corner marshals.
4.8 PROTECTIVE CLOTHING: All protective clothing is a Pre Tech item.
4.8.1 Helmets: All helmets used at a NKA event must be full coverage (full face), with the faceshield installed, designed for competitive motorsports use complying at:
• Snell SA or M 2005 (legal through 2015)
• K 2005 (legal through 2015)
• CMS 2007 youth helmet (legal through 2017)
• CMR 2007 youth helmet (legal through 2017)
• Snell SA 2010 (legal through 2020)
• SFI 31.2a (legal through 2013)
• SFI 41.2a (legal through 2013)
• SFI 24.1/2005 youth helmet (legal through 2015)
• SFI 31.1/2005 (legal through 2015)
• SFI 41.1/2010 (legal through 2020; not legal for vehicles with driver restraint systems)
• BSI A-type and A/FR types are legal for 10 years after date of manufacture.
“Youth Helmets” are not intended for adults regardless of the fit!
4.8.1.1 Helmets must be in “good condition”, with no visible shell damage. If shell damage is
visible, the will not be allowed to be used. Racing helmets are designed for one significant
impact.
4.8.1.2 In the event a driver is in an “on track incident” that results in helmet contact with any
other hard surface, the helmet must be presented for inspection before the driver is allowed
to return to the track.
4.8.1.2.1 Any driver who has lost consciousness or diagnosed with a concussion is not
permitted to race for a minimum of 5 days or until cleared by a Medical Doctor. 4.8.1.3 Improper securing of the helmet strap may result in a black flag and/or disqualification.
4.8.1.4 On-Kart Cameras: are permitted at the discretion of the local track/series. Cameras
are to be hard mounted and NOT affixed to the helmet in anyway.
4.8.2 Gloves are required in all divisions. It is highly recommended to use a glove with a leather
palm.
4.8.3 Driver Apparel: All drivers are required to wear jackets of heavyweight leather or
abrasion-resistant nylon material, full length pants and high top shoes or boots to prevent or
minimize abrasions. One or two-piece suits are permitted; however, one-piece suits are highly
recommended. The Race Officials may modify or supplement this rule to require any additional
protective clothing deemed necessary for the drivers.
4.8.4 Footwear: High top shoes or boots are required. High top shoes shall be laced, buckled
or secured as designed.
4.8.5 Ear Plugs: The use of earplugs by participants, both drivers and pit crews, is strongly
recommended.
4.8.6 Long Hair: If hair extends appreciably from beneath helmet, the competitor must wear a
balaclava to retain hair from extending outside helmet. No hair is allowed to be visible when
the driver is “race ready”.
4.8.7 Helmet Supports: Use of racing helmet supports (rolls) is mandatory for all drivers in
Junior, Junior Sportsman, and Kid Karts (except laydown enduro drivers). They are highly
recommended for all drivers. If a driver loses a helmet support on-track, the driver is subject to
a black flag. Once a helmet support is resecurred, driver may safely return to race.
4.8.7.1 Advanced neck and head supports are highly recommended for drivers of all ages.
Approved devices include:
•
Leatt-Brace Moto Kart and Moto GPX
•
EVS Evolution Race Collar
•
Valhalla 360 Plus Device
4.8.8 Chest & Rib Protectors: All drivers under the age of 13 years in all divisions are required
to wear a chest protection device with SFI specification 20.1 certification any time they are on
the race track.
RECOMMENDED: The use of chest protection is recommended for all types and ages of
kart drivers.
4.9 ELASTIC STOP NUTS ON BRAKE ROTORS: “Nylock”, “Nylon Locking Nuts” and other
such threaded fasteners with plastic inserts or collars are prohibited on any brake hub. These
fasteners are not made for extreme temperature operation and catastrophic failure of the braking
system is possible if the locking part of this type of nut is melted away be the heat generated by
disc brakes. Acceptable alternatives are: all metal lock-nuts, locking washers and double nuts.
4.10 BALLAST: All bolt-on weight must be white in color. All weight added to meet minimum
kart/driver weight requirements shall be bolted and cotter keyed or safety wired to the kart with
a minimum 5/16-inch or 8mm through bolt. Double nuts are permitted with the top nut being
self-locking but threads must protrude. Carrying of ballast on the driver’s person is prohibited.
4.10.1 Any weight over 7 pounds is required to have two (2) 5/16-inch or 8mm through bolts.
4.10.2 No weight shall be bolted to the underside of the kart. Any lead shot or loose material
used as ballast must be mechanically sealed by use of a bolting device. Tape, hose clamps,
tie-wraps or fasteners other than bolts are not legal for attaching ballast weights to competition
karts.
4.10.3 Competitors are charged to make thorough inspections of weight installation to confirm
that they meet the bolt-on requirement. Where weight is attached directly to the seat of a
competition kart, adequate reinforcement must be used to insure that the weight will remain
properly attached at all times.
4.11 STEERING MECHANISMS: Competitors are urged to inspect their kart’s steering
mechanisms, especially in the area of the relief cut at the base section. Verify that the part is in
OEM condition: free of signs of excessive wear or fatigue.
Minimum steering wheel, i.e. butterfly type: 10” minimum diameter, with a minimum of three
spokes, and having a minimum 10” grip length, being no less that 5” grip length on each side.
All divisions.
4.12 NEW DRIVER REQUIREMENTS: New or inexperienced drivers may be required to start
at the back of the pack for their first three (3) races (not heats), at the discretion of the Race
Director. New drivers must display an “X” on the back of their helmet or “Day Glow” orange
number panel on their rear bumper for these first three races. This safety regulation includes
all divisions and classes.
4.13 THIRD BEARING SUPPORTS: Third bearing supports or a suitable guard to contain the
clutch in the event of crankshaft breakage, is required on all 2-cycle karts using an enginemounted clutch. Construction of clutch guards must be 360 degrees and of material equal to
or greater in strength than .090 aluminum. Drill and safety wire at least one (1) support bolt on
third bearing upright plate.
4.14 ROLLER BUMPERS: Roller bumpers are prohibited.
4.15 REAR WHEEL HUBS: It is recommended that rear hubs be drilled and tapped through
the axle to assure the hub cannot slide off the axle. This is not a Pre-Tech Item.
4.16 TIRES:
4.16.1 It is illegal to warm, heat, or scrub tires in any manner on the pre-grid or on the track at
any event. Affects all divisions of karting.
4.16.2 “Tire warmers” are only permitted in individual racer’s pits.
4.16.3 “Tire rotisseries” are not allowed on premises at any event.
4.16.4 Chemical alteration (“doping”) of tires is not permitted in sprint, road-race, and
pavement oval karting. “Doping” is not encouraged for any division, including dirt racing;
however, allowing “doping” at dirt events is left to the discretion of the local track owner or
race director. Drivers and crew members under the age of 14 years are NOT ALLOWED
to apply, mix, transport, or handle in any way tire “preps”, “dopes”, or chemical altering
substance.
4.16.5 Spec Tires: some tracks, clubs, and sanctioning bodies running TrakBOOK may
require the use of a spec tire size and/or compound. The race director has the right to confirm
all competitors are running the required size and/or compound for the class the competitor
has entered.
4.16.6 Check the track’s or event’s entry form for more details; it is the responsibility of the
entrant to adhere to all tire rules/specs for each specific event.
4.17 AIR SHIFTING DEVICE SYSTEMS: Due to safety issues, air shifting device systems are
NOT permitted.
4.18 SAFETY WIRING: Any item that calls for safety wire must be drilled so that the safety
wire can pass through the bolt/pin, not just wrapped around it. Safety wire of .032” or larger is
recommended.
4.19 QUICK RELEASE SAFETY PIN: Quick release safety pin type pins are an approved
replacement for cotter pins.
4.20 RADIOS: Radio communication to or from the driver is prohibited in Sprint and Speedway.
Radios are allowed in Enduro with the following exceptions: Frequency must be furnished to the
Race Director. All radios will be monitored. Any attempt to violate the rules will call for immediate
disqualification from the race.
4.21 DATA TRANSMISSIONS: between the driver or chassis and pit crew or pits is prohibited
while the kart is in motion.
4.22 RACECEIVER: RACECEIVER, “officials to drivers”, communication is not only approved,
but highly recommended for use at NKA events should the track and/or event deem it necessary
to improve the quality of racing. Any NKA track mandating RACECEIVER will receive special
considerations. RACECEIVER will be mandatory in all Kid Kart (5-8 year old class) in 2015.
4.23 RECOVERY/EMERGENCY VEHICLE ON TRACK:
While karts are on the track, no recovery or emergency vehicle should cross, run adjacent to, or
park in close proximity to the track’s surface.
SECTION 5: ON PREMISES REGULATIONS
Only those persons having signed a waiver of liability and with a pit pass shall be allowed in the
pit/restricted area.
5.1 GENERAL REGULATIONS:
5.1.1 POSSESSION OF REGULATIONS: In each pit it is recommended that there be a copy
of these regulations, together with a copy of the rules and regulations for the event in which the
kart is participating so that any dispute may be quickly resolved.
5.1.2 DRIP PANS: It is mandatory that each entrant with chain-drive use a drip pan.
5.1.3 FIRE CODE: All participants shall abide by state and local fire codes.
5.1.4 FUEL DISPOSAL: Any entrant disposing of fuels or lubricants in the pit area or the track
area by pouring or spilling such fuels or lubricants upon the ground may be subject to expulsion
from the event.
5.1.5 USED TIRES: NOT ALLOWED to be left in the pits, paddock, trash, or any location at any
NKA track without the expressed consent of the track owner and/or race director.
5.1.6 TRASH: All competitors are highly advised to bring their own trash bag to the paddock/
pit area and police their own.
5.2 HOT PIT RULES
5.2.1 The hot pit area is reserved for the exclusive use of competing karts and their crews, and
is subject to the control of the Race Director.
5.2.2 All karts will grid in the Hot Pit to enter the track for their respective on-track session.
In race situations, heats or finals, the Hot Pit closes after the field is released onto the track.
Before the green flag is given, any competitor who does not enter the track with the field will
be allowed to join the race, but must start at the back of the pack. If the race has started, any
competitor joining the race from the Hot Pit will be allowed to at the safe discretion of the Race
Director.
5.2.3 SIGNALING: Unless a kart is actually in the pit, only one crew member shall be in front
of the pit for signaling and only for the length of time needed to accomplish the actual signaling
operation.
5.2.4 REFUELING: A kart in competition shall be refueled only in the “hot pit”. The engine must
be stopped and the driver must be out of the kart during refueling operations.
5.3 PRACTICE:
Rules, regulations, and procedures for competition shall apply to all practice sessions as well
as competition.
Extreme caution should be exercised during open practice sessions due to the mixed grouping
of different classed drivers and karts.
Official Practice sessions for a racing event will be run at the length or time designated by the
Race Director.
You may not mix different types of vehicles, such as karts with motorcycles, etc.
5.4 COMPETITION:
• Remain alert. Give consideration to fellow competitors in all areas of safety.
• Adjustment of carburetors and other equipment should be done at safe areas of the track
only. Use extreme caution while tuning on the track.
• When two or more karts enter a corner simultaneously, the lead kart has the right-of-way. All
karts should maintain a constant line through the corner and avoid erratic changes in direction.
Any driver leaving the course or cutting the apex of the corner, attempting to pass another
competitor, is subject to disqualification.
• Any driver slip streaming or drafting another kart should use extreme caution and should be
prepared for evasive action should the lead kart suffer a mechanical failure.
• Bumping, bump drafting, nerfing, blocking, pushing, etc., could be grounds for disqualification.
• Any driver unable to continue because of mechanical failure or lack of fuel, should move their
kart well off the track into a safe location as soon as safe conditions permit. DO NOT leave kart
adjacent to the track at any time.
• At all NKA events, positive effort should be made to prevent rough driving.
5.5 QUALIFYING:
Qualifying procedures are at the discretion of the race director and individual event promoters.
NKA recommends the following procedures for each individual series:
5.5.1 Sprint Karting: 3-5 “hot laps” per class. No more than 15 karts per 2500 feet of track
length at any one time, this allows everyone to have “clean laps”.
5.5.2 Road Race Karting: Qualifying is not recommended as races are long enough to allow
drivers to sort their positions out.
5.5.3 Speedway/Dirt: 2 individual timed laps per driver/per class.
5.6 STARTS:
Utmost caution should be observed during all starts. Avoid sudden changes in direction and if
evasive action is necessary, check first to make sure your course is clear.
NKA Recommends karts start in rows of two (2) and maintain a spacing of 7-10’ between rows.
Spacing between rows allows drivers to concentrate on primarily the driver next to them and not
the drivers in rows behind or ahead of them. Maintaining spacing between rows should greatly
reduce the risk of multi-kart accidents on starts.
5.6.1 Throwing the green flag to start a race is the responsibility of the race director and head
flagman. If either official does not believe the start should happen, they are permitted to wave
the field around for another pace lap.
5.6.2 The pole-sitter and race director controls the pace of the start. It is the responsibility of
the outside pole-sitter to maintain the pace of the pole-sitter.
5.6.3 After the second aborted start, rows 1 and 2 will switch places.
5.6.4 Standing starts are permitted in any class (“Le Mans” style or by rows “shifter style”).
Standing vs. Rolling starts are determined by the Race Director.
5.7 RESTARTS:
5.7.1 There shall be no push-backs or engine restarts allowed once the green flag has been
given. In all karting events, if a kart cannot continue under it’s own power, the driver shall park it
as far off the racing surface as possible and await the conclusion of the race before attempting
to get the kart back to the pit area. Competitors will be scored as they dropped out of the race,
provided that they scale and meet any other post-race requirements.
5.7.2 Any competitor who is (or appears to be) injured or causes an accident, necessitating a
red flag, is not allowed to restart that race without the permission of the Race Director. If the
competitor is able to scale and pass post tech, he will be awarded last place points for that race.
Competitors disqualified for flagrant driving misconduct during a red flag situation will receive
no points.
5.7.3 If a red flag has been thrown, necessitating a restart, a kart that previously dropped
out prior to the red flag can restart the race at the rear of the field, with the Race Director’s
permission.
5.8 SCRATCHED ENTRIES:
5.8.1 In the event of a scratched entry in Speedway, Sprint, or 4-Cycle racing, that space shall
be filled: (1) If on track, by moving forward directly. (2) If in the pits, by crossing over to make
the starting order exactly correct.
5.8.2 In the event of a scratched entry in Road Racing, or sprint racing starting Le Mans style,
all competitors behind the scratched entry will close the gap.
5.9 SIGNALING:
5.9.1 Drivers shall raise one arm over their head to signal following drivers when slowing
abnormally, applying excessive brake, pulling off course, failing to accelerate normally, entering
a road racing scoring chicane, or warning other drivers of impending hazard.
5.9.2 Drivers shall raise both arms over their heads to signal following drivers that they have
no control over their karts after spinning off course or stopping on course due to mechanical
failure. Do not raise arms until the kart is safely stopped.
5.9.3 A driver, when being overtaken by a faster kart, should continue in a straight line and not
swerve to one side or the other while being passed.
5.10 POST RACE DRIVER WEIGHT AND WEIGH-IN: Drivers shall be weighed with their karts
immediately after any competition portion of any event.
5.10.1 Suitable scales should be provided to accommodate driver and kart weighing together.
Drivers shall be weighed with full driving uniform, including helmet, jacket, shoes or boots, etc.,
after time trials and each heat or event. Drivers shall not add any weight to themselves or their
karts between the finish of the competition and weigh-in of driver and kart.
5.10.2 Only one driver or designated crew member per kart is allowed in the post-race technical
inspection.
5.10.3 Any driver leaving an impound area without weighing in shall be disqualified. Post-race
scale and tech areas should be separated from persons other than the competitors.
5.10.4 Drivers have two (at race director’s discretion) attempts to make stationary weight. If
a driver does not make weight at the first attempt, they shall remove the kart from the scales,
“zero” the scales, and immediately make a second attempt.
5.11 POST-RACE INSPECTION: At the end of competition, all karts and drivers shall proceed
directly to the designated impound area to be checked for minimum kart/driver weight, maximum
kart size, engine legality, exhaust system legality, legal attachment of weights, etc. DO NOT
LEAVE THE POST-RACE TECH AREA UNTIL DISMISSED BY THE TECH DIRECTOR; this
may result in disqualification from the event.
5.12 FLAGS: Every competitor is responsible for the knowledge of and adherence to the
following flag rules:
5.12.1 GREEN: Displayed at the start of competition or practice and kept visible as long as the
track is clear for racing.
5.12.2 YELLOW: Caution be prepared to stop. Track partially blocked by an accident or debris.
Slow down, use caution, hold your position; no passing until the track is clear and the green flag
appears again. In Sprint or Road Racing, corner workers may display a yellow flag for incidents
in their area of the track only.
5.12.3 RED: Track is hazardous and unsafe for racing. Slow immediately and stop safely as
directed by designated officials. All entrants shall proceed to designated area. No work on
karts is permitted during the red flag period. Local track safety procedure may supersede these
procedures.
5.12.4 YELLOW AND RED FLAGS WAVED: Restart. Road racing drivers should return to grid.
Sprint and Speedway drivers reform pack for restart at a slow pace.
5.12.5 BLUE WITH ORANGE STRIPE: Faster competitor trying to overtake you: maintain your
current line & allow them to pass.
5.12.6 WHITE: One lap to go.
5.12.7 WHITE WITH RED CROSS: Take care, emergency vehicle on the track. Slow down,
use caution, hold your position, and no passing. This flag may not supersede Rule 4.24: Vehicle
On-Track rule.
5.12.8 BLACK: Continue one more lap at a reduced speed and stop at the designated race
official before resuming competition. Any driver receiving the black flag for a mechanical
problem such as leaking fuel or oil, tire, etc. shall carefully proceed to the designated race
official before resuming competition.
5.12.9 ROLLED BLACK: Warning to driver it is pointed at for rough or aggressive driving.
5.12.10 BLACK WITH ORANGE BALL: Commonly called the “mechanical” black flag. Indicates
to the driver and crew that their kart has a potentially dangerous mechanical problem. Signal
that you are reducing speed, and proceed to the pits for inspection and further instruction.
5.12.11 CHECKERED AND BLACK FLAGS WAVED: Finish under protest.
5.12.12 CHECKERED: Displayed at the finish of competition or practice; one more lap at
reduced speed before stopping or follow Race Director’s instructions.
5.12.13 Should conditions exist whereby drivers cannot easily distinguish the various flags
by color, the Race Director shall call a special meeting to advise all drivers and crew of any
required changes.
5.13 POINTS SYSTEM
To receive points you must pass post-race technical inspection and not receive a Black Flag
while on-track.
Points awarded for finishing positions will be as follows:
1st-200 points + no. of entries
11th-75 points + no. of entries
2nd-175 points + no. of entries
3rd-155 points + no. of entries
All finish positions below 20th position will receive points equal to the number of entries in the
class (21 entries = 21 points).
5.14 COMPLETED RACES
5.14.1 If a race is stopped before full distance, it is deemed “Complete” if 60% of the laps are
completed by the leader at the time of race being stopped.
5.14.2 Scoring will determined via the last fully completed lap. In example, red flag occurs after
the leader as started lap nine, but before the last kart on the lead lap has started lap nine, final
scoring will revert to lap seven.
5.15 Driver Conduct
5.15.1 Sportsmanlike Conduct: It is understood that “light” inadvertent contact will/can occur.
However, intentional and aggressive driving, blocking, “chopping”, and contact will not be
tolerated and can result in penalties, probation, suspension or termination of membership.
5.15.2 Aptitude: defines the ability of the driver to control their vehicle in a safe and proper
manner while on the race track. If it is determined by race officials that the driver’s aptitude is
unfit for the track/event, the driver’s entry should be revoked and his entry fee only shall be
returned.
5.15.3 Lapped Drivers: drivers about to be lapped are responsible for maintaining a consistent
and safe driving line and signaling the lead lap driver on which side to pass on. Lapped drivers
who fail to recognize the blue/orange flag and fail to display professional courtesy are subject
to disqualification.
5.15.4 Reverse Direction: if a driver reverses the direction of travel on-track, be it accidental
or malaises, is subject to disqualification, probation, suspension, or having their membership
revoked.
5.16 Driving in Pits: karts may not be driven in/through pits. If necessary, it is up to the Race
Officials to designate a “testing area” to fire & drive karts outside of the Hot Pit or track area.
5.17 Suggested Exhaust Decibels: If your facility is in an area sensitive to noise, the industry
standard for exhaust decibels is as follows: the legal sound limit for all karts shall be 95 DB (a
weighing scale, slow response), measured 100 feet, 90 degrees from the source, 4 feet from
the ground, and meet any special class requirements. All exhaust systems must remain intact.
SECTION 6: PROTESTS & APPEALS
6.1 PROTEST PROCEDURE:
6.1.1 LOCAL RESOLUTION: Every effort should be made to handle protests at the local level
where witnesses can present evidence pertaining to the protests.
6.1.2 WHO CAN PROTEST: All protests involving specifications legality and driver conduct
shall be submitted by a legal entrant from the same class in which the protested infraction
occurred.
PROTESTER MAY BE REQUIRED TO SUBMIT TO SIMILAR INSPECTION PROCEDURE AS
THE PROTESTED PARTICIPANT.
6.1.3 SINGULAR PROTEST REQUIREMENT: Protests may not be collective. Only a legal
entrant of the class in which the protest is made may protest. Once a protest is properly lodged,
additional protests of the same incident, alleged technical infraction, etc., will not be accepted.
6.1.4 WRITTEN REQUIREMENT:
6.1.4.1 All protests must be submitted in writing on an official protest form, available at
registration, to the Race Director or designated official of the event within 30 minutes after
completion of the event that is being protested or, if in the case of a scoring or technical
protest, 30 minutes after official results have been announced and/or posted.
6.1.4.2 Written protest should refer to the specific specification and/or regulation contained
within this document and refer to same section, paragraph number and page number.
Disqualification appeals must also refer to a specific rule provision.
6.1.5 PROTEST EXHIBITS: Where protests involve specific components such as engine
parts that must be examined, said parts will be impounded by the officials in charge and put
in custody of the Race Director, who will be responsible for delivery of said components to
the TCC. Any components presented for protest inspection that are found to not meet legal
specifications shall be returned at the owner’s cost. At “National” events, the appointed Tech
Person shall have the final determination as to whether an item is legal or illegal. There shall
be no appeal of the appointed Tech Person’s decision.
6.1.6 VIDEO REVIEWS IN PROTESTS: Video and/or photos are not accepted concerning
protests. However, if the track/series operators have a video system in place for review
purposes only, it is left to the discretion of the Race Director to use or not to use to track/series
operated video review system.
6.2 DISCIPLINE
6.2.1 PROBATION: NKA Member Facility may use probation as a disciplinary action for drivers
and crew members.
6.2.2 SUSPENSION TERMS: The NKA Member Facility may suspend for a definite period of
time, or may terminate the membership of any individual upon a finding of a violation of any
rules and regulations of the organization or for any other just cause.
6.2.3 SUSPENSION NOTIFICATION: Notice in writing of such suspension or termination and
of the reason for such action shall be delivered to the suspended or terminated members.
6.2.4 POWER OF SUSPENSION: The power of suspension shall rest solely with the NKA
Member facility, series, or event.
6.2.5 PERIOD OF SUSPENSION: Suspension period and/or termination decisions rest solely
within the discretion of the NKA Member Facility.
6.2.6 DISQUALIFICATIONS: Disqualification from an event precludes the ability to gain points
for that event. Should the point season include a “drop” of an event, that may not be an event
that involved a disqualification.
6.3 APPEALS
To facilitate appeals of a protest by a neutral third party, the NKA recommends the TrakBOOK
Competition Committee. The TCC is a private group of appointed individuals from the racing
community at large. The TCC does not involve any employee or representative of the NKA, nor
any NKA Member Facility. Any charges associated with any protest resolution goes towards
remunerating the members of the TCC for their time and administrative costs of the appeal
(mailings, document copies, etc.).
6.3.1 APPEAL PERIOD: Upon notification of suspension, individual shall have the opportunity
to request an appeal within to 30 days.
6.3.2 TrakBOOK Competition Committee (TCC) Procedure:
Any protest or appeal that cannot be handled at the local level may be individually (facility
and competitor) submitted in writing and signed to the TCC. The TCC decision shall be
final. Competitor and Member Track forfeit all rights to future protests, legal, or other actions
concerning this protest.
6.3.2.1 TCC Non-Technical Procedure:
Non-Technical Protests include anything that is not associated with the engine, chassis, fuel,
or tires of the kart. Such protests must be accompanied by a fee of $250.00 payable to NKA.
The protesting party is responsible for posting the protest fee, and the fee is non-refundable
as this is applied to remuneration of the TCC members time and administrative costs of the
appeal (mailings, document copies, etc.).
6.3.2.2 TCC Technical Review Procedure: All NKA Member Facilities have the right to have
the TCC make the final call on any technical item involved in a protest or appeal.
•
There will be a $250 fee required for this protest & all shipping costs are paid by
Member Track and/or competitor.
•
Parts under protest must arrive at NKA headquarters in a sealed box with each parties’
signature on seal to assure no tampering has occurred.
•
Itemized list of box’s contents must be included in the box and signed by both parties.
•
The participant’s part(s) will have to be sent to NKA’s headquarters for further review
and if deemed legal will be returned within 45 days.
•
Parts deemed illegal will be kept at NKA headquarters for two (2) years and then
destroyed.
SECTION 7: SPRINT RACING KART
Sprint Kart Defined: A racing kart that is driven in a sit-up position. Generally raced on irregular
tracks with both left and right turns and lengths of 1/4 to 1 mile. NKA does not require any
chassis to be CIK-FIA Homologated.
7.1 CHASSIS SPECIFICATIONS
7.1.1 MINIMUM KART WEIGHT: Race ready; dry; Single classes is 85 lbs.
7.1.2 MAXIMUM OVERALL KART LENGTH: 83 inches.
7.1.3 OVERALL KART WIDTH: All 2-cycle standard full-size karts: 55 1/8” in. maximum, 2-cycle
Cadet/Sportsman Chassis: 50 in. maximum. All 4-cycle classes: 50”.
7.1.4 MAXIMUM OVERALL KART HEIGHT: 26 inches.
7.1.5 WHEELBASE: Maximum 43” (109 cm), minimum 40” (101.6 cm) as measured from the
axle wheel centers. Cadet Kart: maximum 41” (104.2 cm) and minimum 35” (89 cm).
7.1.6. MINIMUM TREAD WIDTH: 28 in., measured from inside of one tire to outside of the
opposite tire.
7.1.7 TIRE SIZE: Maximum diameter 12.5 in., minimum diameter 9 in. Only pneumatic type
tires shall be permitted. Specific NKA tracks and/or events may deem a spec tire size at their
discretion.
7.1.7.1 SPRINT TIRES: All competitors in Sprint, 2 and 4-cycle classes, must qualify and
finish all heats on the same set of tires. Tires will be marked after qualifying. It will be left to
the Race Director or Chief of Tech to allow one-for-one replacement of a tire that is damaged
by road hazard or accident; tire should be replaced with one of similar wear. Tires may be
reversed on rims, but must retain original markings.
7.1.17.2 NO CHEMICAL ALTERATION OF TIRES ALLOWED
7.1.8 WHEELS: Shall be void of any defects. Minimum number of wheels is four. Only wheels
of 5 inches and 6 inches will be allowed to compete. No pressure relief devises allowed.
7.1.9 WHEEL BEARINGS: Ground ball or roller type only. Split-race bearing not allowed.
7.1.10 AXELS: Full-size kart chassis can have up to a 50mm outside diameter rear axles, and
Cadet/Sportsman chassis can have up to a 40mm outside diameter axles.
7.1.11 WHEEL WEIGHTS: Stick-on type wheel balancing weights should be taped over as a
backup for OEM adhesive.
7.1.12 FRAME: Main frame members shall be not less than one inch outside diameter by .083
wall thickness, cold roll steel tubing or other material of equal strength. No carbon fiber will be
allowed as an integral part of the go-kart chassis. Integral part of the chassis does not include:
floorpan, seat, bodywork, clutch and engine components.
7.1.13 FRONT BUMPERS
7.1.13.1 Roller bumpers are not allowed.
7.1.13.2 The top of the front bumpers must measure a minimum of 7.750” above the ground
or be CIK front bumper with nosecone. With the CIK front bumper, the nosecone must be
attached to be legal. The top of the CIK front bumper must measure a minimum of 6.5” above
the ground.
7.1.13.3 Must have at least two vertical supports running to the top loop of the bumper or use
two CIK style clamping hooks.
7.1.13.4 Main bumper members shall be not less that .750” outside diameter by .065” wall
thickness, cold rolled steel tubing or other material of equal or greater strength.
7.1.13.5 Front (steal) bumpers can be no wider than the inside of the front wheels.
7.1.14 REAR BUMPERS:
7.1.14.1 The lowest rear bumper’s cross bar must measure a maximum of 7 1/2” above the
ground
7.1.13.7 Rear bumpers that span the full rear track width are not mandatory, but are
recommended: CIK plastic or double steel bar.
7.1.14.2 Main bumper members shall not be less that .750” by .065 wall thickness, cold rolled
steel tubing or other material of equal or greater strength.
7.1.15 NERF BARS:
7.1.15.1 The overall length of the side nerf bar shall be a minimum of 400mm (bottom bar) and
300mm (top bar) measured from the back side of the nerf bar closest to the rear tire and the
rear of the kart in a straight line to where it attaches to the kart at the front.
7.1.15.2 Double high nerf bars are mandatory.
7.1.15.3 Main nerf bar members shall not be less that .750” by .065 wall thickness, cold rolled
7.1.16 DRIVER’S COMPARTMENT: All parts of the driver to be limited to the confines of
the width and length of the kart. If driver’s feet extend beyond leading edge of front tires, an
adequate bumper protection shall be incorporated within the overall maximum length. Driver’s
feet shall not extend beyond bumper when pedals are fully depressed.
7.1.16.1 Seat belts: Prohibited.
7.1.16.2 Seat: No void large enough for any part of the driver’s body to inadvertently pass
through shall be permitted. Only seats suitable for sprint racing competition on sprint tracks
will be allowed.
7.1.16.2.1 The point where the chassis mounted seat strut attaches to the seat should be
reinforced with at minimum a 1-1/4” or 35mm metal washer between the seat and seat strut.
The idea is to help prevent the strut from piercing the seat and causing the driver injury upon
impact.
7.1.16.2.2 Auxiliary seat struts (mounted from seat to axle bearings) may not replace the use
of chassis provided seat mounts. The seat end of the strut must be bolted or affixed to the
chassis with a ty-wrap. The bearing end must be bolted to the bearing carrier with a 5/16”
or 8mm bolt.
7.1.16.2.3 Seat Position: May not extend past centerpoint of rear axle. Minimum Height
(ground to top of seat): see “Figure 7.1.16.2.3.”
7.1.16.2.4 Final decisions on legality will be made by the Race Director and/or race official.
Figure 7.1.16.2.3
7.1.16.3 Belly (Floor) Pan: No void large enough for any part of the driver’s body to inadvertently
pass through shall be permitted. Pan must stay within main-frame rails of kart, be flat, and
only have holes for components (brake discs, sprockets, seat, etc.)
7.1.17 REAR VIEW MIRRORS: Rear View Mirrors are illegal for ALL classes
7.1.18 FUEL SYSTEM:
7.1.18.1 Protection: Any fuel tank that is the highest portion of the kart shall be protected by
a rollbar. The rollbar shall not exceed 26 inches in height and shall be suitable strength and
design to prevent the tank cap from having contact with the ground in the event of an upset.
7.1.18.2 Pressurization: No pressurized fuel tank(s) permitted.
7.1.18.3 Fuel Caps: All flip type fuel caps shall be safety fastened during an event.
7.1.18.4 Fuel Tank: Maximum 9 liter (2.38 gallons) fuel capacity. In sprint chassis only, fuel
tank must be located between the frame rails -except: Comer 50 equipped Kid Karts and Briggs
Flathead engine classes.
7.1.19 BODYWORK: CIK “style” Homologated Bodywork ONLY for 2-cycle Sprint racing; “style”
following the “Spirit & Intent” (ie. no homemade aero bolt-on devices or full-size bodywork on
Cadet chassis).
7.1.19.1 4-cycle Sprint racing bodywork is open. All bodywork must end by centerpoint of rear
axle, must be nonmetallic, and is subject to the NKA safety rules. Local facility may require CIK
bodywork if they choose in 4-cycle classes.
7.1.20 THROTTLE: Karts shall be equipped with foot operated throttle incorporating a dual
return spring system, which closes the throttle when the pedal is released. Hand operated
throttle systems (for handicapped drivers) are permitted at the discretion of the Race Director.
7.1.21 BRAKES:
7.1.20.1 Dual braking systems are mandatory in all 125cc shifter classes and are strongly
recommended for all 125cc classes with karts over 385 pounds. Any kart that exceeds 80 MPH
is also recommended to have dual brake systems.
7.1.21.2 A dual brake system will consist of two independent brake systems on separate disc or
drums. Each system must be fully operational if the other system fails. If a bias control, is used,
it must be able to provide safe operation of one system upon failure of one system.
7.1.21.3 All karts must have brakes operating in such a manner that both rear wheels will brake
equally and adequately. No scrub type brakes are permitted.
7.1.21.4 Hydraulic brake connections must be tight and free of any visible leaks. All brake
lines must be safely routed to prevent any possibility of contacting the ground or any rotating
members of the driveline.
7.1.21.5 The brake pedal must be secured to the kart with cotter pins, safety wire or safety clips
and is to be connected with the master cylinder with a minimum 6 mm steel rod, or OEM cable,
with positive fasteners used at each control end.
7.1.21.6 A safety cable with minimum diameter of 1.8mm is required from the pedal to master
cylinder lever.
7.1.21.7 All master cylinder and caliper mounting bolts and nuts are to be cotter pinned, safety
wired or safety clipped in such a manner that they cannot be loosened without removing the
cotter pins or safety wire.
7.1.21.8 Steel lock nuts, steel nuts with lock washers, or castle nuts with cotter pins or safety
wire are required to hold the brake disk or drum to their hubs. The brake disk or brake drum
axle key will be installed in such a manner that it cannot be lost. NO nylon lock nuts are
permitted on the brake rotor.
7.1.21.9 Since many competition kart brake systems have bolt retained brake pads, they will
be safety wired or cotter pinned where possible. If safety wire or cotter pins are not feasible
due to the design of the brake system (i.e. counter-sunk or counter-bored holes), it is the
responsibility of the driver/pit crew to assure that the pad bolts are torqued to proper tightness
and that appropriate Loctite is used. Torque of brake pad bolts can be a tech item, at discretion
of the race director.
7.1.21.10 For pin retained brake pads, the pins must be secured by cotter pins, safety wire, and/
or spring type pin retainers. When front caliper mounting bolts are also the brake pad retaining
bolts, refer to the preceding paragraph.
7.1.22 STEERING SPECIFICATIONS: The steering shall be direct acting and of suitable design
for maximum safety. Steering design shall be such that the pitman arm cannot rotate over center
and cause reverse steering.
7.1.22.1 All collars and other devices used to retain the steering column shall be secured to
prevent possible loss of the collar.
7.1.22.2 All bolts used in the steering shall be of aircraft standard quality (grade 5 or better) and
shall be 5/16” or 8mm minimum diameter. This does not pertain to king pins or wheel spindles.
7.1.22.3 All steering assembly bolts and nuts, including spindles and kingpins, shall be safety
wired or cotter keyed. All rod ends shall have universal type swivel joints and jam nuts.
7.1.22.4 HOLLOW SHAFT: .700 minimum O.D. steel tubing with a minimum wall thickness of
.0625 in. 5/16” or 8mm minimum diameter fastener at lower end. Steering wheel hub (one piece,
no welding) will be secured with a minimum diameter 6mm thru bolts. If the steering wheel has
a center hole, it may not be large enough to allow the shaft to protrude. Hub minimum O.D. of
1.125 in., flange minimum O.D. of 2.250 in. and a minimum flange thickness of .250 in. Shaft
must protrude into hub a minimum of 1.250 in.
7.1.22.5 Aluminum or other material for steering shaft can be presented to the NKA Technical
Director for consideration.
7.1.23 CHAIN GUARD: Karts shall be equipped with an adequate chain, belt or gear guard
designed to eliminate possibility of personal injury. An exhaust header is not considered a chain
guard.
7.1.24 EXPOSED SPROCKETS: No axle sprockets without a chain are allowed.
7.1.25 CHAIN OILER: The use of any type chain oiler is not permitted.
7.1.26 SPRINT NUMBER PANELS: Size: minimum width 9”, minimum height 7”, as measured on
surface of panel. All panels shall be attached in a safe manner and shall be subject to technical
inspection.
7.1.26.1 The minimum height size for the number itself is 6”.
7.1.26.2 All competition karts must be equipped with four (4) number panels, 1 on the front of
the kart, 1 on each side, and 1 on the rear, meeting the above specifications. Side panels must
be carried between the front and rear wheels. All numbers must be visible with driver in place.
7.1.26.3 All Classes: Number panel to be bolted or riveted to a non-movable position, i.e. nerf
bar, bumpers, stationary bracket. Only exception is when contact paper is used on a fixed nonmovable area, i.e., side pod, side panel, or front nose.
7.1.27 CLUTCHES: The use of clutch(es) is not mandatory, except where specific class rules
supersede. The use of a wet-type clutch is permitted only if the unit is sealed to prevent leaks.
Axle mounted clutches are by Local Option rule only.
7.1.27.1 Spec Clutches: are not allowed to be modified in any way, this includes “excessive
oiling” to increase clutch slip.
7.1.28 SELECTIVE GEARBOX: No transmission, gearbox, or other device which permits a
change of gear or sprocket ratios while the vehicle is in motion is permitted except in 125cc
gearbox classes.
7.1.29 4-CYCLE CRANKCASE OVERFLOW CATCH CANS: Required in all 4-cycle classes.
7.1.30 SPRINT RACING RAIN TIRES: If the race is declared a rain race, the Race Directors
may, at their discretion, waive the “qualify and run all heats” tire rule in Sprint events. The
intent of this rule is to allow the competitor to choose the tire that he/she deems safest in these
conditions, rain or slick. This decision may be made at any time during the course of an event
and is to be used to assure safe completion of the event. Any such announcement of this
change will be made to all competitors at the event at which time they may have the option to
use any tires of their choice.
7.1.31 SUSPENSION: There shall be no type of active, mechanical, or hydraulic suspension.
7.1.32 TRANSPONDERS: NKA suggests transponders be mounted on the center on the
back of the seat. Transponder is to be mounted 25 cm from the ground, with a +/- 5 cm. The
bottom of the transponder is to be no closer than 20 cm from the ground. It is the competitors’
responsibility to ensure that the transponder is in place and operating for the entire race. Karts
that lose their transponder or reception may not be scored. Local Options are at the discretion
of the Race Director.
7.2 SPRINT RACE PROCEDURES
Any major deviation from NKA Race Procedures must be approved by NKA in advance.
7.2.1 NUMBER OF KARTS: The maximum number of karts permitted in any one race during
an event shall be determined by track design, safety of competitors and ability of scorers to
do a reliable job. Since this number will vary from track to track, each club shall use its own
judgment in determining a safe limit. As a default, one kart for every 150’ linear of track is used.
For a one mile circuit, this equates to roughly 35 karts.
7.2.2 STARTING LINE: The starting line can be designated at any place on the track. The
finish line should be at the scoring area.
7.2.3 DETERMINATION OF HEAT: The race director shall determine the amount of laps and/
or time a heat lasts.
7.2.4 JUNIOR SESSIONS: Junior event sessions should be held as separate and distinct
races.
7.2.4.1 Juniors (age 13-15) may, on a local option basis, practice with Seniors, providing safe
track conditions prevail.
7.2.4.2 Junior Sportsman (age 8-12) may not be on track with any competitor running a “fullsize” kart chassis at anytime.
7.3 SUGGESTED SPRINT RACE FORMAT
7.3.1 Draw/Qualifying: Tracks will have at least two format options: draw, draw and invert, or
time trial/qualifying.
7.3.2 TIME TRIAL/QUALIFYING - The procedure for qualifying will be at the tracks discretion
depending on the equipment available. If qualifying is used, the format must be approved by
the NKA sprint directors and/or in the case of a series, the series coordinator(s). The procedure
for qualifying should be published ahead of time.
7.3.2.1 The fastest qualifying lap will determine the line up for the heat, pre-final, or final. Heat
or pre-final finishing positions determine the line up for the final. The finishing positions in the
final will determine the ending finishing positions.
7.3.2.2 If more than the safe number of karts are entered, 80% are determined by qualifying
times and the remaining 20% are determined through a six (6) lap Last Chance Qualifying
race. Refer to rule 7.2.1 for more information.
7.3.3 DRAW AND INVERT THE DRAW: Event format will be to run 2 heats and a final.
Gridding for the first heat will be by blind drawing for position; invert the draw for the second
heat. Starting position for the final will be determined by the lowest points total of heats 1 and
2: 1 point for 1st place, 2 points for 2nd, and so forth. In the event of a tie, the tiebreaker is
the fastest race lap of either heat. The finishing positions in the final will determine the ending
finishing positions.
7.3.4 The pole sitter has the right to choose which side of the track he/she wants to start from
(Local Option). All other rows must stay in assigned lane.
7.3.5 RACE DISTANCES: Race distances are determined by the Race Director and can vary
due to the length of the track, number of classes, weather, and amount of daylight. Listed
below are suggested lap totals based on a .75-mile track distance or 40-second lap time:
7.3.5.1 Kid Karts: 5 Lap Heats or Pre-Finals, 8 Lap Finals (NKA strongly recommends Kid
Karts always be an exhibition class).
7.3.5.2 Drivers 8-12: 8 Lap Heats or Pre-Final and a 16 lap Finals
7.3.5.3 Drivers 13 & up: 10 Lap Heats or Pre-Final and 20 Lap Finals
7.3.6 PRE-GRID: All karts should be in their starting position on the grid one class prior to their
class. If there is a scratch on the grid, the line up shall be adjusted by moving up one position
(crossover) to the next highest position. The Race Director shall determine the pole lane before
the event starts.
7.3.7 WARM-UP AND PACE LAPS: There shall be no “push-backs” once the kart is on the
racing surface. Restarts or working on the kart(s) is not allowed once the green flag has fallen
or the original 90 seconds has elapsed. (The clock shall commence when the first kart leaves
the grid for the race.)
7.3.7.1 At the completion of the 90 seconds, or when the competitors are running and able
to start the race, (whichever occurs first), the starter shall signify a pace lap. All competitors
shall drive to their appropriate grid positions and maintain a slow pace speed. If a kart cannot
continue under it’s own power, the driver shall park his/her kart as far off the racing surface as
possible and move to a safe position off the track.
7.3.7.2 NKA Recommends: competitors shall maintain a 7-8’ distance between rows on all
pace laps until the green flag is waived. NO “bumper to bumper” starts; karting is ‘open-wheel’
racing and therefore a safe distance between rows should be maintained on the start.
7.3.7.3 The pole kart, with Flagman’s approval shall set the pace speed. If a driver is unable
to maintain his position due to mechanical problems or drops out, the balance of the field will
move straight ahead. Drivers must maintain their positions until the green flag drops. If a driver
flagrantly or repeatedly improves his position, or refuses to line up properly, the Race Director
or Starter shall put the driver to the rear of the lineup.
7.3.7.4 If any sprint class cannot receive the green flag in two consecutive laps due to the
failure of the front karts to maintain a proper pace lap speed, the offending kart(s) will be
penalized and moved to the second row. The second row kart or karts will then move up to the
first row and have two chances to take the green flag. The front row will not be penalized for the
actions of the karts behind them.
7.3.7.5 The judgment of the Starter cannot be protested.
7.3.8 START OF THE RACE:
7.3.8.1 Rolling Start: the race shall begin when the green flag is displayed. Karts may not
change their position until the green flag is shown, or at the Race Director’s option the start may
be controlled by the use of cones placed on the center line of the track to keep the two rows of
karts separated. Recommended procedure is to use no more than three cones and they may
not extend past the start line.
7.3.8.2 Shifter karts shall use a standing start. If after the start of the race, the Starter decides
that a restart is necessary (i.e. false start, poor start) he shall signify a restart with a yellow
and red restart flag or yellow and red crossed flags. Karts shall reform to their original grid
positions. The Race Director may impose penalties on the kart or karts that necessitated a
restart condition.
7.3.8.3 Le Mans Style Start: karts are placed in single-file order at a 45 degree angle towards
the first turn of the track with the inside rear wheel on a common and equal starting spot.
Flagman holds green flag up to signify 30 seconds, straight out for fifteen seconds, and then
behind his/her back and can throw it at any time after that. The race is started whenever the
flagman waives the green flag. If a restart is needed before one full lap is completed, a full Le
Mans style restart will be done; any missing karts from the restart, the gap will be filled.
7.3.8.4 The judgment of the Starter cannot be protested.
7.3.9 DURING THE RACE:
7.3.9.1 BLACK W/ ORANGE BALL FLAG (Mechanical Black Flag): The decisions to order
a driver to stop at the pits may be made by the Race Director or Starter if, in their opinion, a
condition exists which could create a safety hazard to the driver or to other competitors. Their
decision may be based on, but not limited to, the following reasons: mechanical conditions,
leaking fluids, inoperative exhaust system and/or safety equipment missing on the driver or
kart. Any driver receiving a mechanical black flag has the option to repair their kart and rejoin
the race. The driver shall receive his appropriate finish points at the end of the race.
7.3.9.2 BLACK FLAG: If the Flagman or Race Director sees a driving infraction (reckless
driving, blocking or unsportsmanlike conduct), the Flagman may display, or at the Race
Director’s orders, will display a black flag to the offending kart. The driver shall signify his
acknowledgement by raising his hand and safely drive to the pit area. The driver shall receive
no finish points for the heat and be placed at the rear of the pack for the next heat. The
Race Director or Starter may signify a warning to a kart with a rolled up black flag for a minor
infraction. The Starter should display the number of the kart being black flagged by means of
a pit board or chalk board.
7.3.9.3 BLUE FLAG or BLUE W/ORANGE STRIPE: A blue flag is shown to a kart or karts being
lapped by faster traffic. When a kart is being lapped, he will give the right-of-way to the faster
traffic and will point (if possible) to the side of his kart that he wants the faster traffic to pass on.
Karts that ignore the blue flag and continually impede the progress of faster karts are subject
to a black flag at the discretion of the Race Director. NKA rules DO NOT require lapped karts
to be pulled off the track.
7.3.9.4 YELLOW FLAG: A yellow flag displayed by a corner worker signifies caution at this
section of the track; no passing allowed, be prepared to stop, use utmost caution until past
this section. Karts caught passing in a yellow flag zone will receive a 30 second penalty. Twin
yellow flags displayed by the Starter signify the complete race course is under a yellow flag
condition; no passing, slow down, be prepared to stop, do not resume racing until the Starter
displays a green flag.
7.3.9.5 Crossed White and Green flags (Optional): A crossed white and green flag signifies the
halfway point of a heat or race. This is an option that the participating club may choose to use.
7.3.9.6 RED FLAG: The red flag shall be displayed when, in the opinion of the Race Director
or Starter, an unsafe condition exists on the track. An injured driver necessitating medical
attention shall automatically require a red flag. The red flag shall only be displayed by the
Starter. When a red flag is displayed, all drivers shall stop in a safe manner as soon as
possible. NO WORK IS PERMITTED ON THE KARTS. If a red flag is thrown before all karts
running have gone through scoring once, then a restart shall be required, using the original
grid lineup. If all karts running have gone through scoring at least once, the last completed lap
scored shall be the lineup for the restart. This restart shall be in a single file. (Karts shall have
90 seconds to start.) The line up order shall be determined by the official scoring sheet. All
karts involved in any incident will be safety checked by the tech committee or their designee
before being allowed back on the track. Notwithstanding the above paragraph, the following
conditions will cause a kart to be penalized on the restart lineup:
7.3.9.6.1 Karts causing an accident, as determined by the Race Director, during or
subsequent to the last officially scored lap shall be put to the rear of the pack. The decision
of the Race Director as to whether a kart caused the incident can not be protested.
7.3.9.6.2 The Race Director may, prior to the restart, black flag a participant who will be
subject to the conditions of the black flag.
7.3.9.6.3 If the red flag has been displayed, necessitating a restart, a kart that previously
dropped out prior to the red flag cannot restart the race.
7.3.9.6.4 In the event that a heat is red flagged, it may be called complete if 60% of the
laps are completed. The finish order shall be as of the last completed lap scored subject to
paragraphs 1, 2 and 3 above. If a red flag is displayed during the last lap of the race, the
race will be terminated with the finish order based on the last completed lap scored. A kart
or karts that necessitated a red flag on the last official lap may, based on the Race Director’s
decision, be disqualified and receive no points for that heat or race.
7.3.10 RACE COMPLETION: A white flag may be displayed signifying the beginning of the last
lap. The checkered flag signifies the end of the race regardless of the actual number of laps
completed. A checkered and black flag displayed together signifies the race is concluded under
protest.
7.3.11 Flagrant track misconduct will result in penalties that may change the final positions for
the heat or race.
7.4 SPRINT SCORING
7.4.1 SCORING FOR HEATS:
7.4.1.1 To break a tie within a class or within qualifying, the fastest qualifying time determines
the winner. If there has been no qualifying and the draw was used for starting position, then
the low draw is the winner.
7.4.1.2 At the finish of each heat, each kart and driver shall pass minimum weight standards.
Failure to pass minimum weight shall result in no finishing points for that heat only.
7.4.1.3 If a participant is DQ’d, the progression will be to move everyone up in the order of the
final finish. No points will be awarded to the disqualified person.
7.4.1.4 If a race is terminated before the completion of all of the heats, because of hazardous
rain or other hazardous conditions, all competitors will receive 1st place points and/or a
makeup race can be scheduled.
7.4.1.5 A sprint entrant must take the green flag and go through post tech to receive points.
7.4.2 RACE CREDIT: Any driver, who makes a valid class entry and has their kart approved
at pre-race technical inspection for a NKA event shall receive participation credit. Drivers and
their karts must be present at technical inspection and on the day of the race in which they are
entered, to receive participation credit.
7.4.3 CREDIT FOR COMBINED SPRINT CLASSES: At events where classes are combined
on a local option basis to form one race due to a small number of entries, the entrant can gain
participation credit for the one class in which they enter and compete.
7.4.3.1 There will be no combining of classes with reduced entry fee.
7.4.3.2 The combining of classes will be at local option and the decision to combine classes
rests solely with the event officials or organizers.
7.4.3.3 The decision to combine classes on a given day must be made prior to the start of any
races on that day.
7.4.4 COMBINING OF SPRINT CLASSES: There should be no combining of sprint classes at
“National” caliber events.
7.4.5 EXCEPTION TO COMBINING OF SPRINT CLASSES: However, at the close of
registration, if there are no conflicts of entries due to the combining of any two classes, it
will then be permissible to combine classes at the Race Director’s discretion. The date and
time of registration closing must be included in all entry blanks and flyers along with tentative
schedules.
7.5 SPRINT CLASSES SPECIAL RULES
7.5.1 KID KART SPECIFICATIONS
There can be 2 kid kart classes, Kid Kart Super (competitive) and Kid Kart (non competitive),
at the discretion of the local Race Director. All rules apply to both classes unless otherwise
indicated.
7.5.1.1 Chain guard to completely cover chain when viewed from above.
7.5.1.2 Chain/Gearing: 219 chain, 10 tooth driver, 89 tooth axle sprocket.
7.5.1.3 No “offset” karts.
7.5.1.4 Wheelbase: minimum 29”, maximum 31”.
7.5.1.5 Width: Front, maximum 40”, as measured to outside of rim/tire (no minimum). Rear
maximum 42”, as measured to outside of rim/tire.
7.5.1.6 Rear bumper: Continuous loop shape with vertical or angled bracing connecting upper
and lower loop rails. Must protect rear tires.
7.5.1.7 Seat may not be offset beyond outside edge of left frame rail.
7.5.1.8 Steering height, maximum 20”.
7.5.1.9 Seat height minimum 10”.
7.5.1.10 Side pods or double nerf bars and nose cones are mandatory.
7.5.1.11 Tires: Open compound. Front size open; Rear tire circumference, maximum 33-3/4”
or 45psi (3.1 bar), measured on the grid before the race.
7.5.1.12 NKA Safety Tech procedures and regulations apply. 7.5.1.13 Weight: Minimum
weight 150 pounds.
7.5.1.14 Kid Kart engines are determined by Local Facility. This can include: Comer C-50,
Comer C-51, or Honda GX-50 Engine (see Engine Specifications section for details.)
7.5.1.15 Kid Kart Super format will be: qualify, pre final, final with the finishing positions of the
final determining the winner. They will begin from a standing start.
7.5.1.16 Delete
7.5.2 Kid Kart “Training” Race Procedures (non-competitive class only): The primary purpose
of the Kid Kart class will be to serve as training/educational process to teach, and improve
driving skills, and teach racing safety to children ages five (5) through eight (8) years old.
Before an on-track event, each child (along with a parent or guardian) will be required to know
and demonstrate a complete knowledge of the use and meaning of the flags used to control
the training race. Each participant will be required to present his/her kart and personal safety
equipment for inspection. A participant or kart will not be permitted to participate if they are not
in complete compliance with all safety conditions, as outlined, and in complete compliance
with local track safety regulations.
PROCEDURES (Non-Competitive Only):
7.5.2.1 Kid Kart participants may not be mixed with any other classes for practice or racing.
7.5.2.2 NKA safety and driver protection rules apply.
7.5.2.3 Race distances of eight (8) lap or eight minute duration are recommended for a Kid
Kart “Training Race”.
7.5.2.4 Training races will start from a standing start, two abreast with each row staggered
from the one in front of them.
7.5.2.5 The training race will proceed under green, barring the need for a yellow or red flag.
7.5.2.6 After weigh-in all participants will proceed to the tech compound for a general critique
of the training race.
7.5.2.7. It is suggested that like awards be presented to all participants.
7.6 Direct drive and remote carburetor adjusters are not allowed in the Junior Classes.
7.7 Use of Starter on TAG classes will NOT result in penalty. Header may be welded as repair as
long as the header flow is not changed.
Basic Sprint Chassis Dimensions.
SECTION 8: SPEEDWAY RACING
Speedway events are contested on oval tracks, which can be either dirt or paved, usually of
distances of 1/8 to 1/4 miles.
8.1 SPEEDWAY RACE PROCEDURES
8.1.1 Proper noise suppression equipment is required for all NKA sanctioned events: 4-cycles
must have headers and mufflers and 2-cycles must have airboxes.
8.1.2 LOCAL OPTION: A NKA SANCTIONED EVENT MAY HAVE IT’S OWN SPECIAL SET
OF RULES SUPPLEMENTING THESE REGULATIONS. SHOULD NKA REGULATIONS
CONFLICT WITH THE SPECIAL RULES OF THE EVENT, IT IS UNDERSTOOD THAT THE
LATTER WILL TAKE PRECEDENCE BY VIRTUE OF THEIR SPECIALIZED NATURE FOR
THE DURATION OF THE EVENT IN QUESTION.
8.1.3 Local option shall be defined as any deviation from standard NKA policy deemed
necessary by the Race Director for a given event; no deviation involving class eligibility or
equipment legality shall be permitted. Local option does not extend to any deviation from safety
rules.
8.1.4 Any deviation from standard NKA race procedures under local option clause must
be published in advance of the event. If not published, it must be on display in the drivers’
registration area prior to and during registration. Sanction fees shall be paid to NKA for any
local option classes run in conjunction with a NKA sanctioned event.
8.1.5 NUMBER PANELS: At all NKA events, all karts must have numbers on all four (4) sides
of the kart of approximately 6” in height.
8.1.6 RESTART AND PUSHBACKS: ONCE THE STARTER DISPLAYS THE GREEN FLAG
AND/OR THE START-UP CLOCK HAS ELAPSED ON THE INITIAL START, THERE WILL BE
NO PUSHBACKS OR RESTARTS. THE PRE-GRID AREA WILL BE CLOSED ON THE DISPLAY
OF THE GREEN FLAG AND WILL REMAIN CLOSED UNTIL THE RACE IS COMPLETED.
POINTS WILL BE AWARDED AS THE ENTRANTS DROP FROM COMPETITION WITH THE
FIRST OUT RECEIVING THE LOWEST NUMBER OF POINTS AND SO ON.
8.2 CHASSIS SPECIFICATIONS
8.2.1 MAXIMUM OVERALL KART LENGTH: 74”
8.2.2 OVERALL KART WIDTH: 50” Maximum
8.2.3 MINIMUM TREAD WIDTH: 28”, measured from the centerline of right tire to the centerline
of left tire.
8.2.4 MAXIMUM OVERALL KART HEIGHT: 26”. This does not include windshield fairing or
steering wheel. Windshield fairing may be installed higher to protect the driver. Fairing cannot
be installed in such a manner as to obstruct the driver’s vision. It can be no higher than the
driver’s eye level while sitting in the kart in a normal driving position.
8.2.5 WHEELBASE: 40” minimum, 50” maximum.
8.2.6 SEAT: No portion of the seat may be located rearward of a plane projected vertically from
the rear of rear axle. Seat height requirements are as follows:
8.2.6.1 Junior 1 classes:10” minimum
8.2.6.2 Junior 2 classes:12” minimum
8.2.6.3 All other classes:14” minimum
Note: Measurement is a vertical plane from ground to highest point on the seat.
8.2.6.4 SEAT ANGLE: Minimum angle 35 degrees, Maximum angle 50 degrees -as raced.
Zero the level to the surface the kart is inspected on.
8.2.7 TIRES: Maximum width of any tire and wheel combination of 10-3/8”.
8.2.8 WHEELS: Shall be void of any defects. Minimum number of wheels is four. Only wheels
of 5 inches and 6 inches will be allowed to compete. No pressure relief devises allowed.
8.2.9 HUBS: Must be metallic materials.
8.2.10 WHEEL/AXLE BEARINGS: Ground ball or roller type only. Split-race bearing not allowed.
8.2.11 FRONT AXLES (SPINDLES): Spindle axle diameter is open. Front axle nuts/bolts must
be cotter-keyed, wired, or pinned. All pieces that allow adjustment must be drilled, wired, and/
or cotter-keyed.
8.2.12 REAR AXLES: Axle must be “live” (driving both wheels equally). Minimum OD is 1”
Maximum OD is 40mm. End of axle may not protrude beyond outside of wheel.
8.2.12.1 Must be of ferrious material: no titanium, carbon fiber, or other “exotic materials”
allowed.
8.2.13 STEERING: must be direct mechanical. “Tiller”, vertical shaft, rack & pinion, and other
“non-traditional” karting steering are NOT ALLOWED. All bolts associated with steering must
be minimum of 1/4” diameter, Grade 5 or higher, and drilled for cotter-key or wire.
8.2.14 STEERING SHAFTS: Quick releases not allowed except in Cage Karts, where it’s
mandatory. No Modifications (welding, cutting, extending, etc.) are allowed.
8.2.14.1 HOLLOW SHAFT: .700 minimum O.D. steel tubing with a minimum wall thickness
of .0625 in. 5/16” or 8mm minimum diameter fastener at lower end. Steering wheel hub (one
piece, no welding) will be secured with a minimum diameter 6mm thru bolts. If the steering
wheel has a center hole, it may not be large enough to allow the shaft to protrude. Hub
minimum O.D. of 1.125 in., flange minimum O.D. of 2.250 in. and a minimum flange thickness
of .250 in. Shaft must protrude into hub a minimum of 1.250 in.
8.2.14.2 SOLID SHAFT: .625” minimum OD steel & one-piece design. Bottom of shaft must
have minimum 5/16” bolt.
8.2.15 BRAKES:
8.2.15.1 Dual braking systems are strongly recommended for all 125cc classes with karts
over 385 pounds. Any kart that exceeds 80 MPH is also recommended to have dual brake
systems.
8.2.15.2 A dual brake system will consist of two independent brake systems on separate disc
or drums. Each system must be fully operational if the other system fails. If a bias control,
is used, it must be able to provide safe operation of one system upon failure of one system.
8.2.15.3 All karts must have brakes operating in such a manner that both rear wheels will
brake equally and adequately. No scrub type brakes are permitted.
8.2.15.4 Hydraulic brake connections must be tight and free of any visible leaks. All brake
lines must be safely routed to prevent any possibility of contacting the ground or any rotating
members of the driveline.
8.2.15.5 The brake pedal must be secured to the kart with cotter pins, safety wire or safety
clips and is to be connected with the master cylinder with a minimum 6 mm steel rod, or OEM
cable, with positive fasteners used at each control end.
8.2.15.6 All master cylinder and caliper mounting bolts and nuts are to be cotter pinned, safety
wired or safety clipped in such a manner that they cannot be loosened without removing the
cotter pins or safety wire.
8.2.15.7 Steel lock nuts, steel nuts with lock washers, or castle nuts with cotter pins or safety
wire are required to hold the brake disk or drum to their hubs. The brake disk or brake drum
axle key will be installed in such a manner that it cannot be lost. NO nylon lock nuts are
permitted on the brake rotor.
8.2.15.8 Since many competition kart brake systems have bolt retained brake pads, they will
be safety wired or cotter pinned where possible. If safety wire or cotter pins are not feasible
due to the design of the brake system (i.e. counter-sunk or counter-bored holes), it is the
responsibility of the driver/pit crew to assure that the pad bolts are torqued to proper tightness
and that appropriate Loctite is used. Torque of brake pad bolts can be a tech item, at discretion
of the race director.
8.2.15.9 Brake Rotor Guard (“Wolfe Plate”): All Speedway karts must be equipped with a
brake rotor guard made of a metallic material.
8.2.16 CLUTCHES: Only dry clutches are allowed in 4-cycle classes; also, NO AXLE clutches
are allowed in 4-cycle classes. 2-cycle classes are allowed dry or wet clutches; however, wet
clutches must not leak.
8.2.17 CHAIN OILER: Prohibited.
8.2.18 CHAIN GUARDS: Must be in place and capable retaining a broken chain.
8.2.19 BELT DRIVES: Prohibited.
8.2.20 TORQUE CONVERTERS & GEARBOXES: Prohibited.
8.2.21 EXPOSED SPROCKETS: No axle sprockets without a chain are allowed.
8.2.22 FUEL TANKS: Must be floor mounted except Briggs Flathead classes. Tanks cannot
be pressurized, must be free of leaks, and have a maximum capacity of 2.38 gallons (9 liter).
8.2.22.1 FUEL PUMPS: Only pulse-driven fuel pumps are legal. No axle or electric pumps
allowed.
8.2.23 SUSPENSION: There shall be no type of active, mechanical, or hydraulic suspension.
8.2.24 TRANSPONDERS: NKA suggests transponders be mounted on the center on the
back of the seat. Transponder is to be mounted 25 cm from the ground, with a +/- 5 cm. The
bottom of the transponder is to be no closer than 20 cm from the ground. It is the competitors’
responsibility to ensure that the transponder is in place and operating for the entire race. Karts
that lose their transponder or reception may not be scored. Local Options are at the discretion
of the Race Director.
8.2.25 REAR VIEW MIRRORS: Rear View Mirrors are illegal for ALL classes
8.2.26 BELLY (Floor) PAN: No void large enough for any part of the driver’s body to inadvertently
pass through shall be permitted. Pan must stay within main-frame rails of kart, be flat, and only
have holes for components (brake discs, sprockets, seat, etc.)
8.2.27 BODYWORK: Brand and design is open. All bodywork must end by centerpoint of rear
axle, must be nonmetallic, and is subject to the NKA safety rules.
8.2.27.1 Maximum height forward of the backside of the front wheels is 17.5”.
8.2.27.2 Maximum height reward of the backside of the front tires is 14”.
8.2.27.3 Column fairing must be lower than the highest point of the steering wheel and have
at least 3” clearance between the wheel and fairing at all points.
8.2.28 WEDGE BODYWORK: Only allowed on 2-cycle Speedway karts. Maximum height is
26” at highest point. From centerline of rear axle to centerline of front axle, overall height must
be in a constant state of decrease. There must be a 1” gap (minimum) between seat and any
point of bodywork.
8.2.29 FRONT BUMPERS
8.2.29.1 Roller bumpers are not allowed.
8.2.29.2 The top of the front bumpers must measure a minimum of 7.750” above the ground.
8.2.29.3 Must have at least 2 vertical supports running to the top loop of the bumper.
8.2.29.4 Main bumper members shall be not less that .750” outside diameter by .065” wall
thickness, cold rolled steel tubing or other material of equal or greater strength.
8.2.29.5 Front bumpers can be no wider than the inside of the front wheels.
8.2.30 REAR BUMPERS:
8.2.30.1 The lowest rear bumper’s cross bar must measure a maximum of 7 1/2” above the
ground
8.2.31.2 Rear bumpers that span the full rear track width are not mandatory, but are
recommended: CIK plastic or double steel bar.
8.2.31.3 Main bumper members shall not be less that .750” by .065 wall thickness, cold rolled
8.2.32 NERF BARS:
8.2.32.1 The overall length of the side nerf bar shall be a minimum of 15.75” (400mm) bottom
bar and 11.8” (300mm) top bar measured from the back side of the nerf bar closest to the rear
tire and the rear of the kart in a straight line to where it attaches to the kart at the front.
8.2.33.2 Double high nerf bars are mandatory.
8.2.33.3 Main nerf bar members shall not be less that .750” by .065” wall thickness, cold rolled
8.2.33 REAR HUBS: No “slip” or “ratchet” hubs allowed. Both drive hubs must be locked in
fixed position so wheels turn equally at all times.
8.3 CHAMP KART SPECIFICATIONS SUPPLEMENT
Unless noted below, refer to section 8.2 for chassis guidelines. NKA strongly recommends using
only a chassis that was commercially produced for Champ Karting in these classes.
8.3.1 MAXIMUM OVERALL KART LENGTH: 95.5”
8.3.2 MAXIMUM WIDTH: 52” outside to outside
8.3.3 MINIMUM WIDTH: 40” outside to outside.
8.3.4 MINIMUM OVERALL KART HEIGHT: 38” ground to top of cage.
8.3.5 WHEELBASE: 42” minimum, 50” maximum.
8.3.6 CAGE TUBING: All structural tubes (everything except side intrusion bar that is
approximately elbow height), must be at least 1.125” with .083” wall mild-steel or stronger
tubing.
8.3.6.1 The “drop” of the cage’s main cage bar between the rear vertical bar and lowest point
in the front is 3” maximum.
8.3.6.2 Top Crossbar must be welded rearward of downward bend of main cage tubes.
8.3.7 REAR CROSSBAR: Horizontal bar on rear of cage, must be 1.125” with .083” tubing.
Shoulder belts must be mounted here.
8.3.7.1 Height from Bottom Rail of Main Frame: Minimum 10”, Maximum 14”.
8.3.8 SIDE INTRUSION BAR: minimum of .750” tubing with .065” wall. This bar can be
removable/replaceable via a slip fit joint welded to the main cage rails.
8.3.9 TOP OF CAGE OPENING: 16”-24” width, 18”-24” length (rear top-rail of cage to crossbar).
8.3.10 CAGE CORNERS: must be rounded. Square, triangulated, or sharp corners are not
allowed.
8.3.11 CAGE WELDING: All welds must be 360 around tubing TIG or MIG welded.
8.3.12 CAGE ATTACHMENT: 4 points to the main-frame minimum and must be TIG/MIG buttwelded.
8.3.13 SEAT BELTS: Mandatory 5-point minimum harness must be commercially manufactured
for motorsports with SFI rating. 2” wide belts are allowed for drivers under 150 pounds; 3” wide
belts are required for drivers over 150 pounds.
8.3.13.1 Lap belts cannot wrap around fame and must be mounted via a welded on steel
seatbelt tab: at least .063” thick and 2” square. See Figure ______ for more details.
8.3.14 ARM RESTRAINTS: Mandatory SFI-rated, must attach to seat belt system, and not
allow any part of the driver’s hand or arms outside the cage when fully extended.
8.3.15 DRIVERS SUIT: Must be SFI 3.2A1 rated or better. This is a fire resistant one-piece suit.
8.3.16 SEAT POSITION: Must be placed so that no portion of the driver’s torso or head is within
6” of the left side of the roll cage’s inner tube.
8.3.17 FIRE EXTINGUISHERS: An on-board fire extinguisher system is recommended, but not
mandatory.
8.3.18 QUICK RELEASE STEERING WHEEL: Mandatory.
8.3.19 BODYWORK: front midget/sprint car style cowling is mandatory. All edges must be
rounded. No bodywork can be attached to side intrusion bars.
8.3.19.1 Tail section bodywork is optional. If used must be midget/sprint styling and be fully
inside rear bumper.
8.3.19.2 NO WINGS or AERO DEVICES ALLOWED.
8.3.19.3 Material must be fiberglass or other similar non-metallic materials.
8.3.20 WINDSHIELDS: Plexiglas or other clear material is allowed up to, but no higher than
the driver’s eye level.
8.3.21 ADJUSTMENTS: No chassis adjustments or devices that allow for adjustments are
allowed while the kart is in motion.
8.4 SPEEDWAY RACE FORMAT
8.4.1 MEETING OF THE DRIVERS AND OFFICIALS: Prior to each race, the Race Director
or flagman shall conduct a meeting of drivers for the discussion and interpretation of the rules
and any specific regulations applying to that race. All drivers are required to attend, and it is the
driver’s responsibility to do so. Any driver failing to attend shall be charged with knowledge of
the matter discussed at such meeting as if he had been present.
8.4.2 PUMP AROUND & PRE-GRID: If applicable, 4-cycle karts are to report to Pump Around
approximately 20 minutes before start of race. Karts must be placed on ground, without tirewarmers, and with tires on before beginning pump around process (for grounding).
8.4.2 METHOD OF STARTING: Unless otherwise specified on the entry form: all races, heats,
or qualification trials shall begin with a flying start. A flying start shall occur when the kart is in
continuous movement up to and across the starting line from any point behind the line.
8.4.3 START: All drivers must form in their proper position on the parade or pace laps.
Parade laps start when the start-up clock has elapsed. Drivers must remain in position unless
mechanical difficulty occurs. In the event a driver drops out, in the pre grid area or on the track,
the balance of the field will move straight ahead. After the 90second start up clock has elapsed,
there will be no working on the kart.
8.4.3.1 Drivers dropping out of the parade or pace laps will not be considered cause for
delaying the start. They must be left behind at the official start.
8.4.3.2 Drivers cannot raise their hand and postpone a start.
8.4.3.3 With approval of the flagman, the pole kart will set the pace for the parade and pace
laps.
8.4.3.4 After the green flag and/or green light is displayed, all drivers must maintain their
relative position until crossing the starting line. If, in the opinion of the flagman, a driver
flagrantly improves his position without cause prior to crossing the starting line, he will be
penalized.
8.4.3.5 The flagman’s decision to penalize in accordance with this rule is not protestable.
8.4.4 MOMENT OF STARTING: The race shall when the flagman displays the green flag.
8.4.5 METHOD OF SCORING: A kart will be officially credited with a lap only when its front
wheels cross the start/finish line.
8.4.6 YELLOW CAUTION PERIOD: The Race Director or flagman is empowered to call at any
time for any reason a yellow caution period. Their decision to call, not to call, or to end a yellow
caution period is not protestable.
8.4.6.1 A kart may be stopped for inspection on the track by a Race Official. Should a
competitor’s motor cease running after kart is stopped by an Official, the competitor shall
have 90 seconds to restart.
8.4.6.2 The yellow starts with the display of the yellow flag and/or light. Drivers are to slow
immediately and are not to pass, and to stay in a single file formation until the track is cleared.
The green flag will then be displayed when the proper line-up order has been verified by the
scorers. The race will resume from the last completed lap. Person(s) causing the yellow flag
will be put to the back.
8.4.7 BLACK FLAGS, STOP FOR CONSULTATION: The Race Director or flagman is
empowered to order any driver at any time to stop at the pits for consultation by displaying the
black flag.
8.4.7.1 The decision to order a driver to stop at the pits may be made, if in the opinion of the
Race Director or flagman, any condition exists which could cause the driver or their kart to
create a hazard to the driver or other competitors.
8.4.7.2 A driver may be ordered to stop at the pits, if in the opinion of the Race Director or
flagman, the driver has flagrantly violated the rules or is driving in a reckless, improper or
unsportsmanlike manner.
8.4.7.3 The decision to order or not to order a driver to stop at the pits is not protestable.
8.4.7.4 Drivers who in the opinion of the Race Director or flagman, clearly ignore the black
flag signal and do not stop at the pits on the next lap after the signal has been given, will be
penalized, in that no laps will be officially credited following the lap in which the signal was first
given. The decision as to whether the black flag was ignored is not protestable.
8.4.7.5 A person receiving the black flag for flagrant driving will receive no points for that
feature or heat.
8.4.8 RED FLAG: When the Flagman displays the red flag, it signifies the stopping of a race
immediately.
8.4.8.1 Should a race be yellow or red-flagged prior to all starting karts completing one lap,
no laps will be officially credited, and a complete restart will be conducted using the original
starting line-up in effect after the original start. The Race Director may institute red or yellow
flag penalties on the first lap if deemed necessary. This will overrule one-lap, accident-free,
or original restart.
8.4.8.2 Should a race be stopped any time following the lap completion as set out in (a) above,
the last official race lap will be that most recent race lap in which the race leader and all
successive karts running on the course, excluding karts passed by the leader during the lap,
were scored at the start/finish line prior to the display of the red flag. or the yellow flag. Within
this lap, each kart will receive credit for its more recently scored lap.
8.4.8.3 In the event of a race continuation other than as set out in (a) above, the karts will be
lined up in single file order beginning with the race leader. The restart order of the remaining
karts will be determined by their physical sequence at the start/finish line during the last
officially scored lap as determined in (b) above.
8.4.8.4 If the red flag has been thrown, necessitating a restart, a kart that previously dropped
out prior to the red flag cannot restart the race.
8.4.8.5 The decision as to whether to red-flag a race is not protestable.
8.4.8.6 The red flag shall be displayed when, in the opinion of the Race Director or flagman,
an unsafe condition exists on the track. The Race Director or flagman will determine which
kart(s) caused an accident (yellow flag) and which caused the red flag. Kart(s) causing a red
flag will not be allowed to restart; all other kart(s) will be put to the back. All kart(s) involved
in the accident will be safety checked. NO WORK IS PERMITTED ON THE KART(S). Karts
have 90 seconds to restart. The decision as to whether a kart caused an accident is not
protestable. Example: Three karts are in an accident, one kart gets upside down and the
other two spin out. All three are involved, but the upside down kart (causing the red flag) will
not be allowed to restart; the other two will be put to the back on the restart.
8.4.9 RACE COMPLETION:
A race will be considered complete at the moment the checkered flag is displayed to any kart,
notwithstanding any subsequent situations, actions, or penalties. The race competition will be
considered complete when, after this moment, each kart still running on the course has, in the
opinion of the Race Director or flagman, had safe and sufficient opportunity to return to the
start/finish line. At this time, scoring will cease and the event is completed. The Race Director
or flagman’s decision in this matter is not protestable.
8.4.9.1 In the event a speedway race has completed 25 minutes on the track, the white flag
will be displayed at that time. In the event the time expires under a yellow flag, the race will
be stopped on the track and the karts will be lined up according to the last completed lap. The
race will end with a yellow/checkered flag finish. The 25 minutes will begin when the first green
flag flies. If the race is stopped due to a red flag, the time will stop until racing can resume.
The checkered flag will always signify the end of the race regardless of how many laps are
completed or how much time has passed. In the event there is a yellow flag after the leader
has taken the white flag, the race will be scored as complete. Should the Race Promoter/
Director deem necessary, i.e. a “big money race”, the 25-minute clock rule can be suspended.
8.4.9.2 The checkered flag will be displayed to the race leader as he completes his last lap
under momentum created by his own vehicle; in (a) above until race competition is completed.
8.4.9.3 Final standings will be determined by the sequence in which the karts completed the
scheduled distance. Karts not completing the scheduled distance will be ranked in order by
total laps completed and sequence of completion. Regional points are awarded accordingly.
8.4.9.4 If a race is stopped by the use of the red flag and is ruled complete, final standings
will be determined by ranking all karts in order by total laps completed and sequence of
completion through the last official race lap.
8.4.9.5 If a participant is DQ’d in tech, the progression will be to move everyone up in the order
of the final finish.
Basic Speedway Kart Dimensions
SECTION 9: ROAD RACE/ENDURO
Generally contested on road courses of 1-1/2 miles or more with sit-up chassis or laydown
chassis for 20-45 minutes.
9.1 CHASSIS SPECIFICATIONS (All “Minimum Width” figures are based on “center to center”
measurements of the rear tires, unless otherwise stated.)
9.1.1 ALL “SPRINT ENDURO” CLASSES REFER TO SPRINT RULES AS THESE SUPERSEDE
ALL ENDURO SPECIFIC CHASSIS RULES
9.1.2 Maximum Length: 97” for single engine
9.1.3 Maximum Length: 110” for 100cc+, duals, and unlimited.
9.1.4 MAXIMUM HEIGHT: 26” (except Unlimited: 34”)
9.1.5 MAXIMUM WIDTH: 50”. (Unlimited Class, maximum width 55”.)
9.1.6 MINIMUM TREAD WIDTH: 30” measured center to center.
9.1.7 WHEELBASE: 50” maximum - 40” minimum (All minimum and maximum “Wheelbase”
figures are based on “center to center” measurements between the front and back axles.)
9.1.8 WHEELS:
9.1.8.1 Only 5” or 6” wheels are allowed; one-piece only!
9.1.8.2 Only four (4) wheels are allowed on a kart.
9.1.9 BUMPERS: Bumpers required front and rear.
9.1.9.1 No part of the feet may extend past the front bumper when pedals are fully extended.
9.1.9.2 Rear bumper shall be a maximum of 7 1/2” above ground level.
9.1.9.3 Bumper diameter shall not be less than 3/4” OD with a minimum of .065 wall thickness,
with at least cold rolled steel strength. Bumper and nerf bars must be made out of steel.
9.1.9.4 If full side aluminum side tanks are not used, there must be a rectangular-shaped nerf
bar in their place. Minimum material being 3/4”, .065 thickness or equivalent. Must be made
out of steel.
9.2 BRAKES: Dual braking systems are recommended for all classes up to stock 100 cc. They
are mandatory on all 125cc, A-Ltd., and up classes
9.2.1 A dual brake system will consist of two independent brake systems on separate disc or
drums. Each system must be fully operational if the other system fails. If a bias control is used,
it must be able to provide safe operation of one system upon failure of one system.
9.2.2 Lay-down brake rules apply to any sprint chassis entered in a lay-down event.
9.2.3 All karts must have brakes operating in such a manner that both rear wheels will brake
equally and adequately. No scrub type brakes are permitted.
9.2.4 Hydraulic brake connections must be tight and free of any visible leaks. All brake lines
must be safely routed to prevent any possibility of contacting the ground or any rotating
members of the drive line.
9.2.5 The brake pedal must be secured to the kart with cotter pins or safety wire, and is to be
connected with the master cylinder with a minimum 6 mm steel rod with positive fasteners used
at each control end. Must be 3/8” or larger.
9.2.6 All master cylinder and caliper mounting bolts and nuts are to be cotter pinned or safety
wired in such a manner that they cannot be loosened without removing the cotter pins or safety
wire.
9.2.7 Steel lock nuts, steel nuts with lock washers, or castle nuts with cotter pins or safety wire
are required to hold the brake disk or drum to their hubs. The brake disk or brake drum axle key
will be installed in such a manner that it cannot be lost.
9.2.8 Since many competition kart brake systems have bolt retained brake pads, they will be
safety wired or cotter pinned where possible. If safety wire or cotter pins are not feasible due to
the design of the brake system (i.e. counter-sunk or counter-bored holes), it is the responsibility
of the driver/pit crew to assure that the pad bolts are torqued to proper tightness and that
appropriate Loctite is used. Torque of brake pad bolts can be a tech item, at discretion of the
race director.
9.2.9 For pin retained brake pads, the pins must be secured by cotter pins, safety wire, or
spring type pin retainers.
9.2.10 When front caliper mounting bolts are also the brake pad retaining bolts, refer to the
preceding paragraph.
9.3 CLUTCHES: Mandatory in all classes.
9.3.1 Wet type clutches are to be sufficiently sealed to prevent oil leakage.
9.3.2 Clutches that can be adjusted while the kart is in motion are not allowed.
9.4 FRAMES: Must be made of a steel material and are subject to a “magnet test”. No carbon
fiber or aluminum frame material allowed.
9.5 NUMBER PANELS:
9.5.1 7”x9” minimum number panels on three sides of kart: front, left, and right side.
9.5.2 Numbers must be at least 6” tall and in contrasting in color to the number panel/back
ground.
9.6 STEERING:
9.6.1 Solid shaft - 5/8 inch minimum diameter equal or greater strength than cold rolled steel.
9.6.2 Hollow shaft - .700 minimum OD steel tubing with a minimum .0625 wall thickness.
9.6.3 One piece keyed or splined steering hub - welding of hub to shaft not permitted.
9.6.4 All steering components shall be safety wired or cotter pinned.
9.7 CHAIN OIL: 4 oz. maximum for 30 minute race, 8 oz. maximum for 45 minute race.
9.8 TRANSMISSIONS: No transmission, gear boxes, or other devices which allow the change of
gear ratios while in motion are allowed except in classes specifically noted as “Shifter Classes”.
9.9 DIFFERENTIALS: None Allowed.
9.10 Sprint Chassis Specifications: as previously stated, all “Sprint Enduro” Classes follow NKA
Sprint Racing chassis rules.
9.10.1 Seat: Height of seat back must be 12” minimum Measured from ground surface. No
head rest allowed. Sprint seat may not extend beyond the rear axle.
9.11 SEAT AND HEAD REST: All enduro lay-down karts must have a seat and head rest. A seat
consists of sides, bottom, and full back. The head rest must have a minimum width of 4 inches
and a minimum thickness of 1 inch.
9.12 SPRAG DEVICES: In all classes, for safety purposes, NKA strongly recommends the use
of sprag-type disengaging axle sprocket hub. This device allows the rear axle to free-wheel in
the event of an engine or gearbox failure.
9.13 AXLE, AXLE NUTS, WHEEL HUBS: End of axle may not extend past the outer wheel or
tire of kart. Axle nuts must be safety wired or cotter keyed. Front and rear slider type wheel hubs
must have one of the approved methods of retention shown below.
9.14 BODYWORK SPECIFICATIONS: NO SHARP EDGES ARE ALLOWED IN BODY
CONSTRUCTION OR DESIGN.
9.14.1 COCKPIT:
9.14.2 LAYDOWN CHASSIS
9.14.2.1 Cockpit must be completely open. (See illustration)
9.14.2.2 Must have 15” minimum clearance from steering wheel to driver’s shoulders.
9.14.2.3 Must have 6” minimum clearance between steering wheel and other bodywork. The
Schroeder hub may be utilized for this 6” rule.
9.14.3 SIT-UP CHASSIS
9.14.3.1 NOSE can extend 3” rearward of the most rearward pedal, when the pedals are in a
normal position (not extended).
9.14.3.2 Minimum clearance between driver fairing and side panel: 4”
9.14.3.3 Minimum clearance between fairing and steering wheel: 2”
9.14.3.4 Driver fairing, 14” max. width, 26” max. height, may attach to nose
9.14.4 ONLY composite, aluminum, or high strength plastic is acceptable material for body
construction.
9.14.5 FLOOR PAN may be no higher than the bottom of the rear axle. Full pans are legal in
all classes except CIK 125cc Sprint. If a full belly pan is not used, in the interest of safety, all
bodywork that extends below the nerf bar must have a minimum 1/2” safety edge.
9.14.6 BODYWORK may surround the tires, but may not enclose them (wheels must be
removable with bodywork in tact). Karts without bodywork (nose, tail, side panels, driver fairing,
full length & width floor panel) may be run with a 20 lb. weight reduction.
9.14.7 NO SKIRTS or aerodynamic sealing devices are allowed behind the front of the front
tires.
Enduro Cockpit Illustration
9.14.8 Nassau panels have a maximum width of 14”, and there must be a minimum of 2”
clearance between the panel and the steering wheel and a minimum of 4” clearance between
the panel and bodywork. Maximum distance between bottom of Nassau panel and floor pan is
2” in all classes using CIK style bodywork.
9.14.9 SPRINT CHASSIS Seat may not extend beyond rear edge of the rear axle. No head rest
allowed. Only a “standard sit-up CIK style seat” is allowed in Sit-Up classes: TAG, Shifter, and
100cc classes designated “CIK Style”.
9.14.10 125CC GEARBOX AND UNLIMITED Exceptions/Extensions:
9.14.10.1 Bubble shields must be non-metallic material.
9.14.10.2 No bodywork will cover feet and ankles with feet in normal position (pedals not
extended).
9.14.10.3 For complete body and/or bubble shield:
9.14.10.4 Bubble shields will be secured to the body with a maximum of four (4) quick release
clips, nylon ties, or similar easily removed fasteners. No solid fasteners will be allowed.
9.14.10.5 When the cockpit cover (bubble shield) is removed, the driver’s body, in a normal
driving position (pedals not extended), will not be covered by any bodywork.
9.14.10.6 26” height rule is waived for non-aerodynamic headrest, gearbox classes only.
9.15 ROAD RACING LICENSING
9.15.1 REQUIREMENTS:
9.15.1.1 A novice driver shall participate and receive a finishing place to receive a Road Race
License. They must grid at the back for three races. A novice permit must be signed by the
race director to receive credit for entry. After which the driver shall mail the permit to the NKA
office to receive a qualified license.
9.15.1.2 Any previously licensed WKA or IKF member can automatically receive a NKA license
by sending a photocopy of the license and membership payment with application.
9.15.2 NOVICE: All novice drivers will participate in a event-run school and 15 minute practice
session, and must demonstrate driving ability before being allowed to compete.
9.15.2.1 At the race director’s discretion Juniors may also run in this practice session.
9.16 ROAD RACING, DETERMINATION OF A WINNER:
An enduro race is a timed event. The main flagman shall be in charge of the official timepiece.
The race will end when the Checkered Flag is given to the overall race leader. All competitors
must complete the lap they’ve started to receive the Checkered Flag. The finishing positions
shall be determined by race order as scored on the checkered flag lap. If more than one kart is
on the same lap, the one that crossed the finish line first shall be considered ahead.
9.17 RACE PROCEDURES
9.17.1 The Race Director, if in his/her opinion, deems it unsafe to continue he/she may call
the event and award points in the following manner: full points if past halfway and 1/2 points is
before the halfway point of the event. At the time the event is called, a signature will be required
by the driver of record to receive race points. (Bonus points, if applicable, are awarded at time
of entry.) The Race Director may not call an event due to rain prior to 12:30 p.m.
9.17.2 All drivers must grid and scale to receive placement points. Any driver attempting to leave
the grid shall be scored ahead of those present but choosing not to race. Drivers choosing not
to race must proceed directly to the scales. Drivers unable to take the green have 15 minutes to
start the race and compete for placement points. The kart may not leave the hot pit area except
to re-enter the track or scale. Weight may not be added by any means, excluding coolant.
9.18 INTERFERENCE
Road races combine several classes on the track competing at the same time. During a race,
it is illegal to intentionally interfere with, or assist, a driver participating in another class in any
way. Any driver that is black-flagged for interference will forfeit all points for that event and their
license will be placed under review by an NKA board, which may result in forfeiture of license
and all point for that season.
Laydown Enduro Chassis Specs:
Enduro Sprint Chassis Specs (above)
Sprint Enduro Seat Inspection Procedures (below)
TECHNICAL INSPECTION GUIDE OVERVIEW
DISCLAIMER: The rules and/or regulations set forth herein are designed to provide
for the orderly conduct of racing events and to establish minimum acceptable
requirements for such events. These rules shall govern the condition of all events
and by participating in these events, all participants are deemed to have complied with
these rules. No express or implied warranty of safety shall result from publication of
or compliance with these rules and/or regulations. They are intended as a guide for
the conduct of the sport and are in no way a guarantee against injury or death to a
participant, spectator or official.
The Race Director shall be empowered to permit minor deviation from any of the
specifications herein or impose any further restrictions that in his opinion do not alter
the minimum acceptable requirements. No expressed or implied warranty of safety
shall result from such alteration of specifications. Any interpretation or deviation of
these rules is left to the discretion of the officials; their decision is final.
Introduction:
The purpose of this tech manual is to provide a uniform set of standards and procedures
to establish the legality of equipment used in sanctioned events.
The Spirit and Intent of the rules is going to be the standard by which karting will
be guided. Event officials are authorized to decide if an equipment modification or
design is an attempt to beat the rules. Event officials can and will disqualify an entry
in violation of the Spirit and Intent of these rules. Any official or representative shall
have the right to initiate action correcting a hazardous condition or a condition not in
compliance with the Spirit and Intent of these regulations.
The intent is that a legal entry be: one driver, one chassis, and one engine (except dual
engine classes would be two engines). After competition starts, (Enduro, when the
green flag drops; Sprint, when a competitor time trials; Speedway, when the first heat
starts) you must have permission from the Race Director or the Tech Inspector, before
equipment is changed. Additionally, any changes to equipment after competition has
started must be performed in the technical inspection area.
Pre-Race Technical Inspection
All karts are required to be presented for Pre-Race Technical Inspection before going
on track at any and all events. Each track will designate an area where Pre-Race
inspection will take place and appoint officials to oversee the Pre-Race Technical
Inspection process.
Pre-Race Technical Inspection Procedures:
•Inspect the driver’s safety equipment to confirm it conforms to current NKA and local
track rules (see Section 4.8 for details).
•Inspect that the kart frame to insure welds are free of cracks or other defects and
that the frame is of common designs for competition karting. If a frame is deemed
“unfit for competition”, it will not be allowed on the track under any circumstance.
•Assure the brakes will lock with adequate pressure applied.
•Assure the throttle will return to a closed position. Throttle assembly and/or throttle
pedal must have at least two (2) return springs/mechanisms.
•Inspect that there are cotter pins, safety pins, and/or safety wire on:
• Every steering bolt including tie rods, steering shaft bottom, steering shaft to
frame collar, steering wheel hub, and at least three (3) bolts on the steering wheel
itself
• Both front kingpins
• Both main pedal bolts
• At least two (2) brake rotor bolts
• At least two (2) brake caliper bolts
• At least one (1) brake master cylinder bolts
• Each mounting point of the brake lever extension (between brake pedal and
master cylinder)
• Every bolt on ballast weights
•Assure all ballast is painted white or another bright color and contrasts well with the
racing surface.
•Assure the front axles have wire or a safety clip on the spindle.
•Inspect that each nerf bar is held on with bolts, locking through pins, and/or springs
as the factory intended.
•Inspect the exhaust pipe/system for proper security including proper retention for
that specific class (can be left to the judgment of the local official).
•All fuel line connection points should be wired or plastic ty-wrapped to prevent
separation.
Pre-Race Technical Inspection Form: It is highly recommended that every entrant be
given a “Pre-Race Technical Inspection Form” before each event. This is to be filled
out, signed by driver or owner and technical inspector, and collected by technical
inspector before the kart is allowed on-track. A sample of this form can be found on
www.nkaonline.com.
Any kart failing Pre-Race Technical Inspection has the opportunity to correct any/all
problems as pointed out by the officials are re-submit the entry for approval.
Decisions of the Race Director and Chief Technical Inspector are final and nonprotestable.
Post Race Technical Inspection
At the end of competition, all karts and drivers shall proceed directly to the designated
impound area to be checked for: minimum class weight, chassis legality, engine/
exhaust/clutch legality, fuel/oil legality, and tire legality. Refusal to report to Post-Race
Technical Inspection will result in an immediate disqualification from the event.
No ballast can be carried by driver; all ballast weight must be bolted to the kart. Drivers
may not add weight to themselves or their karts between the finish of competition and
weigh-in.
Engine legality shall be determined according to specifications contained in this
technical inspection manual, unless otherwise specified by the Officials/Promoter of
specific events.
All engine parts should be inspected at ambient temperature, not “hot”. It is the
decision of the driver/owner to determine when engines are at an acceptable “ambient”
temperature for inspection.
NO GO GAUGES: The NKA Rules and Technical Guide requires the use of “No
Go” gauges to determine the legality of certain chassis specifications, engine parts,
exhaust systems, and carburetors. A No Go gauge is a non-adjustable tool that is
inserted into a specified opening. A part is illegal if the No Go gauge enters the
opening being measured. When measuring a chamfered or angular opening, the No
Go gauge may enter the chamfered area, but the gauge may not be self-supporting
when the part is rotated at any angle.
Note: A Vernier caliper is not a No Go gauge and may not be used to tech any opening
where this manual specifies a No Go gauge. The technical inspector may utilize
whatever NKA approved tools deemed necessary to accomplish tech procedures with
exception of No Go gauges.
SPEC FUEL PROGRAMS: It will be the responsibility of the individual tracks/series
to determine which fuel tech will be utilized for the series and it should be printed at
least ten (10) days ahead of any event.
Additional Fuel Notes:
Additional tests may also be done.
No cool cans or insulated tanks allowed.
All fuel, 2 & 4 cycle, must be run at ambient temperature and may be checked at
any time.
Argument against spec oil: Competitors should be able to select the type of lubricant
be it castor, synthetic, or petroleum based as long as it does not adversely affect
the meter. This eliminates the event promoter/officials from criticism over detonated
engines. Tests have shown most of the common lubes are within 4-5 points of each
other.
All other existing tests could be utilized, as long as the spec gas was used as a
comparison basis.
If additional lab tests are required, they become very simple—competitor’s sample
compared to the spec test sample.
It is the intent of this program to establish a minimum basis spec gas tech program. If
a competitor is found to have added toxic substances to his fuel, he will be subject to
a one-year suspension for the first offense; lifetime suspension for a second offense.
If tracks suspect toxic substances being added to the fuel, a sealed sample should
be taken and given to a NKA official to be turned over to the NKA office for testing.
SECTION 10: 100cc or LESS 2-CYCLE TECHNICAL INSPECTION
GUIDE
10.1 Yamaha KT-100S Inspection Procedures
Unless otherwise noted, the Yamaha KT-100S should utilize one carburetor and only
stock Yamaha parts and be in OEM (stock) appearance.
10.1.1 External modifications that do affect performance are allowed (i.e. painting of
cylinder head fins for advertising).
10.1.2 Pulse line hole may be relocated. The internal diameter of the Pulse Line pipe
may not exceed 0.125” (+.003”). An NKA approved No GO gauge is the acceptable
way of inspecting the Pulse Line pipe.
10.1.3 Bore and Stroke (Displacement):
Maximum Bore: 2.090” (52.96mm)
Maximum Stroke: 1.816” (46.13mm)
10.1.4 Walbro WB3A Carburetor is the only carburetor allowed for the JR. 2 and SR.
classes. Listed below are some specific specifications regarding this carburetor:
•Diaphragms are a non-tech item, but must be stock appearing
•Shimming of the inlet spring is allowed & inlet spring is a non-tech item
•Fuel must pass through internal OEM passages only
•Both internal screens must be installed at all times
•Machining of the throttle shaft is not allowed.
•All components not specified here must be stock appearing
10.1.4.1 WB3A bore must be “as cast” and will not exceed 1.010” (25.65mm) at any
point. Venturi .950” no-go. (See Figure 10.4.4.1 for details):
10.1.5 Walbro WA55B JR. 1 Carburetor. Listed below are some specific specifications
regarding this carburetor:
•Diaphragms are a non-tech item
All components not specified here must be stock appearing
10.1.6 Carburetor Inlet Track Length: minimum is 2.600” and maximum is 2.800”.
Inlet track length is measured from the face of the piston to the surface on which the
carburetor mates with. Carburetor base gasket should be removed for tech.
10.1.7 Phenolic Spacer must be “as cast” straight bored with a minimum ID is 1.000”
and maximum ID is 1.050”; the maximum thickness is 0.405”.
10.1.8 Aluminum Carburetor Mount Plate: Hole size 1.050” maximum, 1.000”
minimum. Straight bore.
10.1.9 Airbox/filter Adapter: cannot be “velocity stacked” or shaped to act as a “ram
air” tube. For JR 1 Walbro WA55B carburetors, the minimum inlet hole size is 0.750”.
Must be straight bore.
10.1.10 Cylinder Head & Sparkplug: Any machining of the cylinder head or cylinder
liner to accept a sealing device is illegal unless it is stock equipment on the engine.
Spark plug must be a stock (unmachined) 14mm x 3/4”-reach spark plug.
10.1.11 Combustion Chamber: Volume shall be a minimum of 11cc. Measured to
top of the spark plug hole with L.A.D. (cc) gauge installed and torqued to 160 inchpounds. Combustion chamber must be of conventional design and centered.
10.1.12 Head Gasket: Yamaha KT100S material should be copper or aluminum.
Engine to have a ring type head gasket.
10.1.13 Cylinder: All ports are to be “as cast”. The only exception is the aluminum in
the inlet track behind the carburetor and exhaust outlet areas can be “blended”. The
original design of the intake and exhaust ports must be maintained; however, surface
finish in these areas only is a non-tech item. Port edges may not be chamfered.
In summary, these rules do not allow:
•Grinding the aluminum to change the roof angle of the transfer ports.
•Grinding the port to alter the height, width or angle.
•Grinding to change the shape or size of the passages from the cylinder base to the
port.
•Grinding to match the cases to the port passages (when cylinder is or is not reversed.)
•Sandblasting, glass beading, peening, etc. are not a substitute for “as cast” condition.
•Due to the manufacturing procedures, it is possible that some engines may have
slightly “broken” port edges. When this exists, it is uniform on all port edges (tops,
bottoms and sides) of all ports in the cylinder. The intersection of the port edges and
the cylinder wall must still be within tech measurements. As the bore size increases,
the amount of “break” diminishes. If the cylinder bore size is 2.065” or larger, no
“broken” edges are allowed.
•Cast iron may show grinding nicks only. Aluminum only may be blended in the inlet
track behind carb and exhaust outlet areas only. Aluminum surfaces non-tech in these
two areas only.
10.1.13.1 Blowdown: Maximum: .420” Minimum .370”. Any “blowdown” measurement
outside of these parameters will be deemed illegal and presumed to have been
“altered” in violation of “as cast” rule stated above.
Yamaha KT-100S Port Diagram
10.1.14 Inlet Opening: Check with dial indicator, .775 ATDC maximum.
10.1.15 Cylinder Position: It is legal to turn the cylinder and piston 180° on the Yamaha
KT100S. Matching of the transfer passages in the case and cylinder is not legal.
10.1.16 Exhaust Port Opening: Check with dial indicator. Piston travel from top dead
center to exhaust opening, 1.155-ATDC or greater.
10.1.17 Old Style Cylinder (if allowed by Local Option)
Exhaust Port Rule: On old cylinders, one and only one exhaust port opening can be
ground upon. This includes bottom, sides and top of that one port opening. The cast
iron can be ground on. The other exhaust port opening must be in “as cast” condition
on the cast iron. Aluminum surface will remain non-tech. Great care must be taken not
to remove too much cast iron on the .140” minimum rib width side. Widening of this
port is allowed but remember 1.551” is the no-go size. New cylinders still go with “as
cast” in all port areas including exhaust.
10.1.17.1 Old Style Tech will be done using new dimensions listed and must follow
items 10.1.13 thru 10.1.16, with the exception that one exhaust port may have
the cast iron ground to bring exhaust measurements closer to specification. The
remaining other exhaust port must have unaltered “as cast” finish on cast iron.
10.1.17.2 The competitor’s engine that has been ground is required to mark the
aluminum surface on top of the cylinder next to the stud located above the port
altered. An arrow or an X will do.
10.1.17.3 The altered port top must be ground a minimum of 90° to cylinder wall.
10.1.17.4 No chamfer allowed.
10.1.17.4 No free-porting of exhaust ports.
10.1.17.5 Exhaust gasket must be in place.
10.1.18 New Style Cylinder Identification: To specify a new type cylinder, a boss
with 787 and Y3 or Y4 is located between the bottom and first fin approximately in
the center of the cylinder. One boss each side. Any means taken to revoke or alter
identification boss will result in that cylinder being inspected as a new style.
10.1.18.1 No grinding on cast iron on these cylinders unless using “Option 2” under
10.1.13.1.
10.1.18.2 Tech will be done using new dimensions listed and must follow items
10.1.13 thru 10.1.16.
10.1.19 Piston: Piston must be an approved single ring only and stock appearing.
Legal pistons are Yamaha, Burris, Wiseco, Vinart, RKE 787, and KSI. All approved
pistons should have name cast inside. Bottom of piston should be 90° to sides.
Transfer area of piston must be cast, no scalloping. Piston top must be dome shape.
Rings must be of magnetic material. No holes may be drilled to lubricate exhaust rib.
Any machining to the top of the piston is illegal. All pistons are subject to a comparison
to a known stock piston.
See Figure 10.1.19 for more information.
Yamaha Piston
10.1.20 Connecting Rods: Approved connecting rods are Yamaha part numbers 7F611651-01, 7F6-11651-02 and 50W-11651-00 only. The connecting rod must be of
original manufacture and stock appearing with no machining, grinding, blending or
polishing allowed. Shot peening the connecting rod is allowed. Center of crankshaft
journal diameter to center of wrist pin diameter 3.932” minimum, 3.942” maximum.
Top or bottom-guided rods and bearings allowed.
10.1.21 Wrist Pin: Stock type only. No tapered pins. See Figure 10.1.21
Figure 10.1.21 Yamaha Wrist Pin
10.1.22 Crankshaft: Crank assembly must be original manufacture and stock
appearing. Shot peening and polishing is allowed. Outside diameter measurement:
3.410” minimum, 3.435” maximum. Minimum width 1.790”. Concentric bushings may
be applied to crankshaft journals to repair worn crankshaft is non-tech. Bushings
may be tack welded to hold in place. See Figure 10.1.22 (top right of page) for more
information.
10.1.23 Spacers: The top end of the rod shall have two or more spacers with loose or
caged type bearings. Thrust washers for Piston Port engines are non-tech items, but
must be in place. Spacer material may be steel, brass or aluminum. The bottom of the
rod should have a caged type bearing and no spacers.
10.1.24 Bottom location of connecting rod approved with:
10.1.24.1 Two 1mm lower washers
10.1.24.2 One 13.95mm width lower cage
10.1.24.3 Should not be a combination of top and bottom location.
Figure 10.1.22 Yamaha Crankshaft & Rod Assembly
10.1.24.4 The crankpin should be hollow and must have two steel plugs in place.
Crankpin minimum id after plug is removed is .400. Plug must be of drillable
material and the competitor is responsible for removal of plug in tech.
Note: New crankpin with no plugs approved. Maximum id .425 no-go.
10.1.25 Ignition: must be of original manufacture and stock appearing. Ignition keys
must fill slots in crankshaft and flywheel. Key width non-tech. Any means taken to
alter the coil position is illegal.
Machining the shanks of coil hold-down screws to provide additional coil position
adjustment is not allowed.
Modifying the flywheel in any manner in order to change ignition timing is illegal.
Right hand flywheel on straight shaft ignition timing is illegal. Right hand flywheel on
straight shaft ignition has machined side out, left hand flywheel has cast side out.
Ignition bearing may be removed. Taper bore flywheels have only one keyway and
both rotations have the cast side out.
New Style Flywheel: 7F6-85551-01 (Std.), 7F6-8555-51 (Rev.) are approved. Main
body thickness: .817” minimum (ears may be removed).
External coil damage may be repaired with silicone or epoxy.
Note: The Atom ignition module is approved for the KT100S. Only one module may
be used.
Old Type Flywheels: Minimum diameter: 2.350”; Minimum width: .827”.
10.1.25.1 Ignition Timing Inspection: Timing Inspection must take place BEFORE
the rotor nut is loosened from the crankshaft.
10.1.25.2 With the piston at Top Dead Center to .015” below Top Dead Center, the
leading edge of the rotor’s magnet is required to line up with the trailing edge of the
ignition coil leg. The coil’s trailing edge is the bottom leg on clockwise ignitions.
10.1.26 Yamaha Exhaust Specifications
The Yamaha KT-100S engine can be fitted with a variety of exhaust systems to form
different classes based on speed (power), experience, and spec racing. Described in
section 10.1.26-10.1.28 are the various exhaust options and tech procedures.
•“Pipe” classes are non-tech other than the maximum ID of the exhaust header of
1.780” and only one exhaust port gasket at .200 maximum thickness is allowed.
•All Yamaha box muffler 2-Cycle classes are only allowed one exhaust port gasket at
.200 maximum thickness. Any attempt to by-pass the restricted muffler is illegal. No
coatings (to be run as manufactured).
10.1.27 RLV YBX Box (3 hole) Muffler:
10.1.27.1 End cap must be removable for inspection of baffle with three each .380”
maximum no-go holes spaced approximately 1.250” apart.
10.1.27.2 End cap to have three each .380” maximum no-go holes rotated 180° or
opposite baffle exit holes. In operation, end cap and header flange must be securely
fastened with no leakage. Must be installed in “up” position.
10.1.27.3 Check of exhaust gas leakage may be made by a gas leak detector.
10.1.27.4 Must be run on kart in horizontal position.
10.1.27.5 EGT probe is allowed. Must not leak. Must be located between header,
flange and front cap.
10.1.27.6 Additional support brackets from chassis or engine are allowed as long as
they don’t improve performance.
10.1.27.7 In order to extend the life of the Superbox muffler series, RLV is applying
a spot of weld on the center of the end cap (this is not a performance issue). This
affects part numbers: 7502,7540, 7542, 7544, and 7548.
Figure 10.1.27 describes the measurements for the RLV YBX Supercan series
mufflers:
10.1.28 RLV SSX and SSX-V Box (4 hole) Muffler:
10.1.28.1 The four (4) external exhaust holes are to be checked with a .500” No-Go
gauge.
10.1.28.2 Remove the three (3) cap screws to inspect the fourteen (14) inner baffle
holes, a missing screw is grounds for disqualification.
10.1.28.3 The 14 inner baffle holes are inspected with a .380” No-Go gauge.
10.1.28.4 Check of exhaust gas leakage may be made by a gas leak detector.
10.1.28.5 Must be run on kart in horizontal position.
10.1.28.6 EGT probe is allowed. Must not leak. Must be located between header,
flange and front cap.
10.1.28.7 Additional support brackets from chassis or engine are allowed as long as
they don’t improve performance.
10.1.28.8 In order to extend the life of the Superbox muffler series, RLV is applying
a spot of weld on the center of the end cap (this is not a performance issue). This
affects part numbers: 7502,7540, 7542, 7544, and 7548.
Figure 10.1.28 describes the measurements for the RLV SSX Supercan series
mufflers:
Popular KT-100 Classes (class name: suggested weight range, ages, and special
notes).
•Junior 1: 230-250 lbs., 8-12, WA55B carburetor with SSX or YBX can and “Cadet” or
“Sportsman” chassis. 4.50-4.60” tires on all corners.
•Junior 2: 290-310 lbs., 13-15, WB3A carburetor with SSX can. 6.00” tires on the rear
are typical.
•Senior-Masters YBX can: 330-370 lbs., 15+, WB3A carburetor with YBX can. 6.00” or
7.10” tires on rear (track/series to spec). Masters typically age 35+ with local option of
driver weighing over 200 lbs. allowed.
•Senior-Masters Supercan: 330-370 lbs., 15+, WB3A carburetor with SSX can. 6.00”
or 7.10” tires on rear (track/series to spec). Masters typically age 35+ with local option
of driver weighing over 200 lbs. allowed.
•Senior-Masters Pipe: 330-370 lbs., 15+, WB3A carburetor with open exhaust as
described in 10.1.26. 7.10” rear tires. Masters typically age 35+ with local option of
10.2 KPP 100cc Specifications
Section 10.5 covers specifications for the Komet Piston Port engine class. This engine
is also, or formerly, known as “HPV”, “KPV”, and/or “K-71”. However, no K-71 parts are
allowed to be interchanged with KPP parts.
10.2.1 External Modifications: that are non-performance enhancing are legal (such as
painting the cylinder head fins). No anodizing of any engine parts is legal.
10.2.2 Pulse Line: hole maximum size is .128” as measured with a No-Go gauge.
Maximum Bore: 2.085” (52.96mm)
Maximum Stroke: 1.816” (46.13mm)
10.2.4 Walbro WB3A Carburetor is the only carburetor allowed for the JR. 2 and SR.
classes. Listed below are some specific specifications regarding this carburetor:
•All components not specified here must be stock appearing
10.2.4.1 WB3A bore must be “as cast” and will not exceed 1.010” (25.65mm) at any
point. (See Figure 10.1.4.1 for details)
10.2.5 Walbro WA55B JR. 1 Carburetor. Listed below are some specific specifications
regarding this carburetor:
All components not specified here must be stock appearing
10.2.5.1 WA55B bore must be “as cast” and will not exceed 0.630” at any point. The
Manifold for the WA55B must be as (See Figure 10.1.5.1 for details)
10.2.6 Carburetor Inlet Track Length: minimum is 2.600” and maximum is 2.800”.
Inlet track length is measured from the face of the piston to the surface on which the
carburetor mates with. Carburetor base gasket should be removed for tech.
10.2.7 Carburetor/Throttle Adapter:
The KPP aluminum carburetor adapter with a maximum ID of 0.0630” is the only
legal metallic adapter. Non-metallic carb/throttle insulator minimum diameter is
1.000” and maximum 1.050”. With the non-metallic insulator installed, the minimum
inlet tract measured from the carburetor-mounting adapter to the face of the piston is
2.900” and maximum of 3.000” –both with carburetor base gasket removed.
10.2.8 Airbox/filter Adapter: cannot be “velocity stacked” or shaped to act as a “ram
air” tube. For JR 1 Walbro WA55B carburetors, the minimum inlet hole size is 0.750”.
10.2.9 Cylinder Head: The sparkplug hole, combustion chamber, and squish band
must have a common axis (concentric) to the head bolt circle within 0.020”.
10.2.10 Combustion Chamber Volume: minimum of 11cc as measured with an NKA
approved beret, LAD sparkplug hole tool, and Marvel Mystery Oil.
10.2.11 Ports (intake, exhaust, and transfer): must be original design (shape). The
aluminum and cast iron finish of intake and exhaust ports is non-tech; however, must
fit stated dimensions (see 10.2.10-10.2.11 & Figure 10.2.11 KPP Ports). Transfer
ports are to remain “as cast”.
Figure 10.2.11 KPP Ports
10.2.12 Intake Port: has a maximum width of 1.380” and height is maximum of 0.775”
to the bottom of the port from TDC.
10.2.13 Exhaust Port: height is a maximum dimension of 1.155” at TDC.
10.2.14 Both the PVL 458 coil, rotor, and stator and Selettra P3356 ignition with black
or blue P3356 coil are legal. Regarding the Selettra P3356: finned rotors are legal
with no modifications. All parts are subject to comparison between known “stock”
pieces. Mixing of PVL and Selettra parts is not legal.
10.2.15 Piston and Rings:
10.2.15.1 KPP OEM factory pistons and rings are the only ones approved at this
point by NKA; part number is 1319. The piston name and mold number will be cast
on the inner skirt surface.
10.2.15.2 The bottom of the piston may be machined for port timing adjustment;
however, it must maintain a 90 degree profile to the sides of the piston and must be
symmetrical front and back
10.2.15.3 The top of the piston must maintain dome shape
10.2.15.4 Chamfering of the bottom of the piston is legal up to .030” from the bottom
of the piston to the sidewall of the piston
10.2.15.5 Piston rings may not drop through cylinder and have a maximum ring gap
of 0.030”
10.2.16 Piston Wrist Pins:
10.2.16.1 Must be KPP OEM, steel.
10.2.16.2 ID maximum: .410”
10.2.16.3 OD .550” minimum and .552” maximum
10.2.16.4 Minimum length: 1.565”
KPP Piston
10.2.17 Connecting Rod: Must be KPP OEM. Minimum connecting rod length, centerto-center, is 3.774”-3.786”.
10.2.18 Crankshaft: Must be KPP OEM. See Figure 10.2.18 for more details.
10.2.19 Clutch:
10.2.19.1 KPP spec drum with the 3 factory installed external cooling holes on the
outside of the drum face, this is the only legal drum.
10.2.19.2 No modifications of any kind are allowed; must be used as manufactured:
no removal of material from any surface.
10.2.19.3 No oiling or greasing of clutch is allowed.
10.2.20 Clutch Stall Check:
•Test stall limit is 5,000 RPM with driver in kart.
•Place in front of rear wheel a ¾” x ¾” bar.
•Start the kart & driver must run over the bar with the clutch engaging under 5,000
RPM to be legal.
10.2.21 Exhaust System: must be KPP stock as per class (KPP Sportsman, KPP Jr..,
KPP Sr.)
10.2.21.1 Header: No modifications of any kind with the exception of a single hole for
an EGT sensor. Sensor must be in place or the hole must be filled.
10.2.19.2 Flex: solid pipe must be used. Length of the flex, measured from the
backside of the piston to the outer end of the flex pipe is: 12-12.5” for Sportsman
and Junior Classes and 10” minimum for Senior Classes.
KPP Exhaust
10.2.19.3 LOCAL OPTION: It is up to the local track/club to allow the older “HPV”
exhaust systems. Keep in mind if this option is enacted: the length from piston face
to end of connector pipe on HPV is 1/8” longer than Komet OEM part.
Popular KPP 100cc Classes (class name: suggested weight range, ages,
and special notes).
•Junior 1: 230-250 lbs., 8-12, WA55B carburetor with KPP spec Junior 1/Sportsman
exhaust pipe with 12-12.5” flex range for Junior 1 and Junior 2 classes. “Cadet” or
“Sportsman” chassis. 4.50-4.60” tires on all corners.
•Junior 2: 290-320 lbs., 13-15, WB3A carburetor, spec KPP exhaust with 12-12.5” flex
range. 6.00” tires on the rear are typical.
•Senior-Masters: 330-370 lbs., 15 & Up, WB3A carburetor with KPP spec exhaust pipe
and 10” minimum flex length. 7.10” tires on rear (track/series to spec). Masters typically
age 35+ with local option of driver weighing over 200 lbs. allowed.
10.3 Comer 80cc (K-80 and W-80) Specifications
This section covers stock piston port valve engines under 81cc. Engines to have
single cylinder a single stock carburetor. Unless otherwise specified, all parts are to
be of the original manufacturer and stock appearing. The following engines have been
homologated for this class: Comer K-80, Comer W-80.
Maximum Bore: 2.055” (52.20mm; chrome bore)
Maximum Stroke: 1.500” (38.1mm) (+/-.004”)
10.3.2 Exhaust Intake Timing: As per NKA specs, cc: 8.5 with L.A.D. gauge plus .200
spacer, new style only; 7.5cc minimum old style (no L.A.D. gauge).
10.3.3 Non-Tech Items: Unless otherwise specified, non-tech items include gaskets,
oil seals, bearings and cages, fasteners, and crankpin. Bearings are a non-tech item
but must be of same internal diameter, width, and outside diameter as original parts.
10.3.4 Exhaust, Intake and Transfer Ports: Check port heights and widths per following
diagrams (Figure 10.6.4) Note all dimensions are to opening and do not include radius
allowed for chroming of bore. Ports are not ground or polished. Grinding, polishing,
and shot blasting are not allowed. Exhaust/intake check with .120 round rod. Exhaust
minimum 1.140, intake maximum .460.
Comer K-80 Ports
10.3.5 External Modifications: Those that do not affect a performance gain are legal.
10.3.6 Engine Additions: Conventional air cleaner and starter nut. Engine must be run
with supplied clutch and muffler. All must be as supplied with engine and all subject to
tech. Clutch 12 tooth, #219 chain.
10.3.7 Carburetor: HL166 only. See Figure 10.3.7 for more details:
10.3.8 Ignition: Bosch is slotted for adjustment. Adjustment slots are cast in and
cannot be machined for more adjustment. Spark plug must be 3/8” standard or 1/2”
reach plug.
10.3.9 Head Volume: 7.5cc minimum old style (no L.A.D. gauge). 8.5cc minimum new
style (with L.A.D. gauge) and a .200 spacer.
10.3.10 BASE GASKET: .003 minimum.
10.3.11 Piston and Rings: Piston must say USA and rings must be in place and not
fall through cylinder.
10.3.12 Exhaust: stock and unaltered. See Figure 10.3.12 for more details:
K-80 Exhaust
Popular Comer 80cc Classes (class name: suggested weight range, ages,
and special notes).
•Cadet, 220-235 lbs., 8-12, Comer 80cc engine with minimum gear ratio of 5.25 and
4.50-4.60” tires on all corners. “Cadet” chassis only.
10.4 Comer C-50 & C-51 Specifications (Kid Kart Engine)
NO Modifications! Engine must remain totally stock and compared to known stock
parts. Piston rings must be present and cannot fall through cylinder. All gaskets must
be in place. Silicone is not considered a replacement for gaskets. Seals, bearings and
gaskets are non-tech. Seals must be unaltered. Head cc 7.3cc minimum. No LAD
gauge.
Additional information is available in the figure below:
10.4.1 Carburetor: model SHA 14-12L Dellorto, with .475” No-Go Venturi inside
diameter. All parts as cast.
10.4.2 Carburetor jetting is allowed.
10.4.3 Taping or covering of the shroud in any manner is illegal.
10.4.4 The magneto key and keyway must be unaltered and in place. The key and
keyway can be inspected by removing the flywheel nut.
10.4.5 Stock filter and at least one stock filter element (unmodified) must be used.
10.4.6 Combustion Chamber: As manufactured. All threads are to be intact. Plug
threads may be repaired, but must be full length.
10.4.7 Port Height Check: Check with 3mm (0.120”) rod 3.00” long (max) inserted
approximately 0.25” into port. Rod should be unsupported. Exhaust: 1.200” min
Intake: 0.370” max.
10.4.8 Base Gasket: Must be in place
10.4.9 Bearings: No Ceramic Bearings Allowed
10.4.10 Ignition Timing Check: Remove starter cover, install dial indicator in plughole, zero at TDC. Rotate flywheel counter clockwise until first magnet is completely
exposed. Rotate back clockwise until right edge of magnet aligns with left edge of
coil. Dial indicator reading 0.050” - 0.060”. See Figure 10.4.10:
Popular Kid Kart (Comer 50cc) Classes (class name: suggested weight
range, ages, and special notes).
•Kid Kart Novice: no minimum weight, ages 5-7 (must pass Race Director’s approval
to compete), 8.90 spec gear with a maximum rear tire circumference of 33.75”
•Kid Kart: 150 lbs. minimum, ages 6-8 (must pass Race Director’s approval to compete),
8.90 spec gear with a maximum rear tire circumference of 33.75”
SECTION 11: 125CC “TAG” TECHNICAL INSPECTION
“TAG” stands for “Touch and Go” that is electric start. The engines are 125cc 2-cycles
with low-stall engagement clutches and have exhausts restricted per each engine’s
individual specs.
The rules listed below are specific to NKA and may not cohere
with the TAG rules used by other sanctioning bodies. Check the “local/event specific”
rules to assure your engine is compliant. NKA takes no responsibility for engines that
do not comply with another sanctioning bodies “tighter” rules.
11.1 WHERE DISCREPANCIES IN TOLERANCES ARE FOUND, THE MOST
LIBERAL TOLERANCE APPLIES.
11.2 Starter and Battery: must be in place; however, if the engine will not start with the
on-board starter system, it is legal to start the engine with an external starter without
penalty.
11.3 Approved Airboxes
11.3.1 CIK approved/homologated airbox with two (2) 23mm or less diameter and
minimum 95mm length tubes is approved.
11.3.2 K&N with rigid internal filter. Two (2) tubes only 23mm or less diameter and
minimum 95mm length tubes are approved.
11.3.3 Any RLV airbox and filter combination with two (2) tubes only 23mm or less
diameter and minimum 95mm length tubes are approved.
11.3.4 Aftermarket internal air filters are allowed, must be unmodified.
11.3.5 Rotax airboxes are only allowed on Rotax engines.
11.3.6 Rotax engines must use airbox and filter and be compliant with RMC rules.
11.3.7 The internal side of the mounting flange of the rubber boot may be trimmed flush
with airbox flange lip.
11.3.8 Airbox must be in place at the end of event.
11.4 Carburetor:
11.4.1 Only the supplied OEM carburetor is approved for each engine.
11.4.2 No machining of any surface is permitted.
11.4.3 All replacement parts must be OEM.
11.4.4 Any non-performance enhancing throttle body is approved.
11.4.5 Jetting is open except with Rotax engines which must conform to Rotax Max
Challenge™ rules.
11.5 Ignition Systems: OEM only as supplied by manufacturer. All parts must be in
place, and static timing must be as factory settings.
11.6 Pistons, Rings, and Wristpins: OEM as supplied. NO modifications or coatings
allowed.
11.6.1 Burris Racing aftermarket pistons for Rotax are approved.
11.7 Bearings: Must be of original OEM type steel bearings: NO ceramics, dual-ball,
angular contact, or other “exotic” bearings allowed.
11.8 Exhaust System: OEM for each specific engine only. No plating or other coatings
allowed. EGT sensors are allowed; however, if sensor is not present the hole must be
plugged.
11.8.1 Exhaust Flex Pipe: can be solid or flexible material and is a non-tech item.
11.9 Clutch: as supplied from manufacturer. No machining or other modifications
allowed. Must slip at or below 6,000 RPM, excessive grease or oil that enhances
engagement is illegal. Entrant may be subject to clutch stall test (similar to KPP) if
technical inspection officials believe it is necessary.
11.10 Cooling System: Radiator size and placement is open. Contents are open as
well with the exception of any coolant containing ethylene glycol (anti-freeze).
11.11 Internal Modifications: No internal modifications, including the addition or
deletion of parts, are permitted.
11.12 Reeds and Cages: reeds are open; however, must be stock thickness +/-0.002”.
Reed cage must maintain OEM appearance: no grinding or polishing is allowed.
Deburring is allowed.
11.13 Ports: As manufactured. That being said, all manufacturers have some
hand grinding to reduce imperfections in manufacturing; every effort will be made to
distinguish between manufacturer’s grinding and owner’s grinding for a performance
gain.
11.14 Seals: must be of OEM size, type, and shape. Must also be installed as
manufacturer intended (no reverse seals).
11.15 Gaskets: non-tech.
11.16 Rods: OEM as manufactured, no removal of material is allowed.
11.17 Cylinder Head: must be stock. Combustion area must stock appearing. Each
engine will have a specific squish regulation.
11.17.1 CC test is done without LAD plug in sparkplug hole, measured to the top of
the sparkplug hole as raced.
11.17.2 Squish Test: using .062” (approximately) solder,
insert it between the piston and head parallel to the piston wrist pin. Using hand tools
(not the electric starter) “squish” the solder. Removed the solder and measure with
calipers.
11.18 Crankshaft: OEM as supplied by manufacturer per engine; no interchanging
between engine brands is allowed. No metal removal, shot peening, polishing, or
other modifications allowed.
11.19 Crankcases: OEM with no metal removal, coatings, or other modifications.
Repair of main bearing pockets is allowed; however, relocation is not.
11.20 Painting/Anodizing: is allowed as long as it does not enhance performance
(i.e. painting the head to promote engine builder or anodizing aluminum starter braces
is permitted).
11.21 Rotax FR125: All specs per Rotax Max Challenge™ rules and regulations.
11.22 IAME Parilla Leopard (2008 & before):
11.22.1 Stroke: 54mm
11.22.2 Bore: 54.30mm maximum
11.22.3 Rod Length: 102mm
11.22.4 Piston Type: Single Dyke Ring
11.22.5 Port Height (Maximum Degrees): 171
11.22.6 Port Height LAD Tool: 1.380”
11.22.7 Cylinder Head Volume (cc): 9.5cc
11.22.8 Minimum Squish: 0.026”
11.22.9 Reed Thickness: 0.012”
11.22.10 Ignition: Selletra 4 pole or Digital K
11.22.11 Timing: Fixed
11.22.12 Clutch: Shoe (3) IAME
11.22.13 Carburetor: Tillotson 334A or AB
11.22.14 Exhaust: IAME Leopard Pipe with adjustable flex or 2010 IAME pipe 1-piece pipe
with tuning spacers behind header.
11.22.15 Exhaust Length Minimum: 15.75” from backside of header flange (where header
meets cylinder), around the outside of the pipe, to the 1st weld at the end of the divergent
cone. *Local Option: can be adjusted as needed for specific track.
11.22.16 Junior Modifications: Substitute Senior header for Leopard Junior Header with
25mm or 30mm restrictions (Local Option for Restriction size).
11.23 IAME Parilla Leopard MY09:
11.23.10 Ignition: Selletra 4 pole or Digital K
11.23.13 Carburetor: Tillotson 334A or AB
11.23.14 Exhaust: IAME Leopard Pipe with adjustable flex or 2010 IAME pipe 1-piece pipe
with tuning spacers behind header.
11.23.15 Exhaust Length Minimum: 15.75” from backside of header flange (where header
meets cylinder), around the outside of the pipe, to the 1st weld at the end of the divergent
cone. *Local Option: can be adjusted as needed for specific track.
11.23.16 Junior Modifications: Substitute Senior header for Leopard Junior Header with
25mm or 30mm restrictions (Local Option for Restriction size).
11.24 PRD Fireball 2008 (black head & machined ports):
11.24.10 Ignition: OPPMA PVL
11.24.11 Timing: 0.075”-0.090” BTDC
11.24.12 Clutch: Shoe (3) No Springs
11.24.13 Carburetor: Tillotson 360A
11.24.14 Exhaust: PRD Pipe with adjustable flex.
11.24.15 Exhaust Length Minimum: 15.75” from backside of header flange (where
header meets cylinder), around the outside of the pipe, to the 1st weld at the end of
the divergent cone. *Local Option: can be adjusted as needed for specific track.
11.25 Vortex Rok TT:
11.25.1 Stroke: 54mm (no stuffers)
11.25.4 Piston Type: Single Rail Ring
11.25.10 Ignition: Selletra
11.25.11 Timing: 0.070”-0.085” BTDC
11.25.12 Clutch: Shoe (3) Vortex
11.25.13 Carburetor: Tillotson 3604A
11.25.14 Exhaust: Vortex Pipe with adjustable flex.
11.25.15 Exhaust Length Minimum: 15.75” from backside of header flange (where
header meets cylinder), around the outside of the pipe, to the 1st weld at the end of
the divergent cone. *Local Option: can be adjusted as needed for specific track.
11.26 Motori Seven TAG:
11.26.1 Stroke: 54.40mm
11.26.10 Ignition: Selletra or PVL
11.26.11 Timing: 0.060”-0.075” BTDC
11.26.12 Clutch: Shoe (3) with springs
11.26.13 Carburetor: Dell’Orto VHSH30CS
11.26.14 Exhaust: Motori Seven pipe 1-piece pipe with tuning spacers behind header.
11.26.15 Exhaust Length Minimum: N/A
11.27 Sonik TX 125cc (see 2013 TrakBOOK for more information). NKA is not
supporting this engine any longer as it has been out of production for over three
years.
11.28 IAME Parilla Dragon:
11.28.6 Port Height LAD Tool:
11.28.10 Ignition: Selletra Digital K
11.28.13 Carburetor: Tillotson 334A, AB, or AA
11.28.14 Exhaust: IAME Leopard Pipe with adjustable flex.
11.28.15 Exhaust Length Minimum: n/a
11.29 Mini Rok TAG Cadet 60cc:
11.29.5 Port Height (Maximum Degrees): 116.5
11.29.6 Port Height LAD Tool:
11.29.7 Cylinder Head Volume (cc): 7.5cc with LAD tool
11.29.9 Reed Thickness: n/a
11.29.10 Ignition: Selletra
11.29.11 Timing:
11.29.12 Clutch: Shoe non-adjustable Vortex
11.29.13 Carburetor: Dell’Orto PHBH 18 with #40 slid, W23 needle, #60 Outer Pilot,
#50 Inner Pilot, 266AN Emulsion Tube, and 4 gram floats. Only Main Jet and Needle
Clip position are allowed to be changed.
11.29.14 Exhaust: OEM Vortex Mini Rok
11.29.15 Airbox: OEM Vortex Grey Single Inlet Hole 23mm x 95mm (+/-1mm).
Popular TAG Classes (class name: suggested weight range, ages, and
special notes).
•All TAG style classes can as a “single engine class” if the local track/series so desires.
•If all/multiple engines are allowed at certain track, obviously, a certain engine might
perform better at one track vs. another. Therefore, the weights listed below are just
guidelines and can be adjusted as needed per track.
•TAG Cadet w/Mini Rok Engine: 220-235, 8-12, 4.50-4.60” tires on all corners.
•Most TAG engines have a “Junior Option”, such as a restricted header, carburetor
restrictor, and/or different rev-limiters or external engine components to limit power.
Junior TAG is typically 310-330 lbs. and include ages 13-16.
•TAG Senior-Masters: weights vary per engine (see below for recommended starting
points for each engine) , 15+, Masters typically age 35+ with local option of driver
weighing over 200 lbs. allowed.
TAG Engine Recommended Weights:
•Parilla Leopard (All), PRD, Rotax FM125: Junior 320, Senior 350, Masters 380.
•Vortex Rok TT, Motori 7, Sonik TX, IAME Dragon: Junior (if applicable) 320, Senior
375, Masters 400.
SECTION 12: 125cc SPEC HONDA TECHNICAL INSPECTION
GUIDE
This section covers specifications for the 1999-2002 Honda CR125R engine formula,
commonly referred to as “Stock Honda”.
12.1 Airbox: engines must have either an air filter or CIK style airbox installed
at all times, some tracks mandate an airbox for noise control. Airboxes can have
a maximum of three inlet tubes of 29mm +/-1mm diameter and 95mm in length.
Running an air filter inside the airbox is allowed and is a non-tech item as long as it
seals around the airbox. No modifications of any kind are approved to the airbox or
filter.
12.2 Parts: from 1999 through 2002 Honda CR125R engines may be interchanged.
12.3 Cylinder Head: must retain OEM without any machining or modifications.
Removal of mounting boss and modifications to the water outlets for the purpose of
hose connection are allowed.
12.4 Cylinder Head Squish: is measured with .060” solder at two points parallel to
the piston wrist pin. Measurement should be as follows: .045” to .050”.
12.5 Cylinders: 1997 through 2002 cylinders are legal. No Modifications are
permitted! OEM measurements fall within this range: 1997-1999 cylinders: 3.311”3.316” and 2000-2002 cylinders: 3.307”-3.312” overall height.
12.6 Power Valve Plugs: Stock power valves may be removed and aftermarket plugs
used; however, this must be done with no modifying of the cylinder and no machining
of the exhaust port. Power valve plugs must be matched outside of the cylinder and
re-inserted. Cylinder mounting flanges for retaining cylinder to cases may be spot
faced in the area where the nut meets the flange only. Some factory grinding, done
prior to the Nikasil process, is present on many cylinders. NKA Technical Director
reserves the right to approve or disapprove any cylinder supplied by Honda and not
modified.
12.7 Piston, Ring, and Wristpin: all must be OEM with No Modifications. The only
exceptions are: 1) it is permitted to “lap in” the bottom of the ring, and 2) Wristpin
clips are non-tech.
12.8 Crank and Rod Assembly: Must be OEM Honda with No Modifications. Main
bearings and seals must be OEM too. Flywheel must be in place, and keyway must
remain unmodified and in use. Polishing of the crank to “slip fit” the bearings is
permitted.
12.9 Gearbox (Transmission): Five or six speed gearboxes are permitted. Six
speed boxes must be 1994-1996 OEM: no aftermarket parts are permitted. No
polishing, grinding, or other modifications of any kind are permitted!
12.10 Clutch: all parts must be OEM with No Modifications of any kind. All clutch
plates, as per manufacturer’s design, must be in place.
12.11 Engine Cases: must remain OEM with No Modifications of any kind, this includes lapping of bearing pockets. Non-performance enhancing modifications to external parts is allowed, for example, machining of kick-starter boss and installing a plug
in the kick-starter shaft hole.
12.12 Exhaust Systems: exhaust flange and silencer are non-tech items, but flange
must be OEM length and dimensions. The following exhaust pipes are legal, and must
remain as manufactured:
12.12.1 RLV R2 standard stinger (part # 6800)
12.12.2 RLV R2 w/ cross stinger (part # 6800/c)
12.12.3 RLV R4 (part # 6830)
12.12.4 RCE T-3
12.12.5 Hi-Tech 125
12.13 Stator: Must be OEM 1999 with no modifications, including wiring. Flywheel key
must remain in place with no modifications. The stock slotted plate or SKUSA™ plate,
both allow a limited amount of timing adjustment. Any attempt to exceed this adjustment amount is not permitted. No modification to the hold down bolts or to the plate is
permitted. No other modification to any of the ignition components that changes static
timing is permitted beyond what the stock plate or SKUSA™ plate allows.
12.14 Coil: must be 1999 OEM with No Modifications. No advanced ignition control
can be performed on the coil. The lead and ground wires can be replaced to facilitate
mounting. Ground cable type and size are non-tech.
12.15 Water Pump: must be OEM, No Modifications are allowed.
12.16 Gaskets, Bearings, and Seals: bearings and seals must be OEM. Gaskets
must be to OEM specifications, thickness, and numbers. The use of common sealants
is permitted.
12.17 Reed Cage, Manifold, and Reeds: The reed cage and manifold must remain
stock 1999 OEM CR125 (Honda Part Number 16221-KZ4-A10 – marked KZ4M) with
no modifications. The reed cage must be 1999 CR125 (PN 14100-KZ4-J11). For longevity reasons, aftermarket replacement reeds will be allowed, including mono reeds
or stiffeners. Note that this only allows reeds that may be installed without modification
to the 1999 reed cage and does not permit multi-stage reeds.
12.18 Carburetors:
12.18.1 For Jr.. Stock Honda: Keihin 35mm PWK, Keihin 38mm PWK, or Keihin
38mm PWM are legal.
12.18.2 For all other Stock Honda classes: Keihin 38mm PWK or Keihin 38mm PWM
are legal.
12.18.3 Pump around systems are allowed.
12.18.4 Carburetor bore measurement will be determined at the engine side of the
slide. Bore may not exceed the designated maximum diameter of 38.6mm in an area
.400” (10mm) wide measured inboard of the slide.
12.18.5 No additional performance components may be added to the carburetor. No
internal or external performance modifications to the carburetor are allowed, such as
polishing, boring (including oval boring), or modifying internal passages.
12.19 Junior Stock Honda: all of the above rules apply with the additional regulations
listed below:
Must use RLV airbox with two 23mm inlet tubes, RLV Part Number: 0300 (red) or 0301
(black).
Popular 125cc Honda Shifter Classes (class name: suggested weight
range, ages, and special notes).
•Junior: 325-335, 12-15, install carburetor restrictor to limit power.
•Senior-Masters: 375-400, 16+, and Masters typically age 35+ with local option of
FOUR CYCLE ENGINE SPECIFICATIONS
SECTION 13: Honda GX-50 Kid Kart Engine Specifications
This is a newly adapted package for 2014. More information on converting to the GX50
for Kid Karts, contact NKA. The GX-50 is a small 4-cycle engine that comes sealed
from HPD with a spec clutch. Testing has shown it to be a reliable and cheap alternative
to the Comer C-50 for Kid Karts.
Rules are supplied by Honda Performance Development:
General Rules:
1. Engine: Honda GXH50 as supplied by Honda Performance development.
a. Engine seal: As installed by HPD. If seal damaged, missing or disturbed in any way
the entrant will be disqualified.
b. Gas tank: Must remain on engine in factory location and mounting. Fuel line must
run directly from tank to carburetor.
c. Fuel: 87 octane pump gas or VP MS93. Fuel to be specified by the series/track. No
additives allowed. Failure to meet fuel inspection results in a disqualification.
d. Carburetor: KEIHIN BF32E
No change or modification to the carburetor is permitted.
Throttle plate: # 140 as manufactured with sharp edges. Must retain stock screw.
Main nozzle: Minimum length 1.140”
1. Through hole: .055” No go
2. Two holes at bottom, 180° apart .028” No go
3. Eight holes above bottom band 90° apart .020” No go
4. Four holes at top 90° apart .020” No go
Float: F3
Main Jet: #52S. Go .50mm; No-go .52mm
Pilot Jet: #35
Maximum venturi size (no-go): 15mm
All jets must be TIGHT. Loose jets will be disqualified.
e. Throttle linkage must be as supplied by HPD.
f. Air Filter: Must remain stock, with stock foam insert. No internal or external
modifications of any type.
g. Spark plug: NGK CR5HSB or Denso U16FSR-UB. Washer must remain on both
spark plugs.
h. Kill switch: Stock switch must remain connected. An additional switch may be
installed in reach of the driver.
Page 2 of 4
i. Oil Alert switch: Yellow wire must be disconnected or cut.
j. Oil: SAE 10W-30 or SAE 30 only. Hondaline oil recommended. No exotic oils such
as those containing “combustion enhancers”. Tech on oil using a refractometer is
encouraged.
k. HPD chain cover to be used. (pending availability)
l. Clutch: HPD supplied. White and Blue spring are only legal options. No mixing of
colors. No modifications or oiling allowed. Stall speed 2400.
m. Gearing: 16:89 or 15:89. Series/track to decide which gearing spec. Max 8000
rpm. No mixing of gear combinations within class.
n. Exhaust: As supplied, modification or repair not allowed. Cracked or broken exhausts
will be disqualified. Any evidence of exhaust leaking is grounds for disqualification.
o. No additional decals or other signage allowed on engine except for Honda or
Honda Racing HPD.
2. Engine Mount pattern: 112mm X 54mm
GX 50 Ignition Timing Procedure:
• Remove the starter assembly and large cover.
• Install a dial indicator in the spark plug hole, using a 10mm X 1.00 adapter.
• Make sure the indicator has a ball end to ride across the crown of the piston without damage.
• Place light grease or oil on the ball.
• “0” the indicator at top dead center, it does not have to be on the compression stroke as long as piston is at TDC. • Rotate the flywheel clockwise until the two magnets on the flywheel are to the right of the coil.
• Rotate the flywheel counter clockwise until the left hand edge of the left hand coil mount leg is in line with the left hand edge of the left hand magnet.
• Dial indicator reading should be between 245” and 265”.
External visual check of engine for required components: Pipe and muffler,
shrouds and sheet metal, oil level sensor (this can be observed from outside).
A. Blocking Air Flow to the engine: Only factory heat shield is legal. No device
may be used that will/or appear that it may impede airflow into the engine cooling
system. This may require that the engine be run at a speed above idle by the tech
personnel at the scale after the car has qualified or raced.
B. Engine should be at ambient temperature when presented to Pre-Grid.
Intake:
1. Remove Carburetor:
A. Only stock Honda insulator gasket between black plastic insulator and head. Air
passageway in insulator will not be altered in anyway.
2. Insulator thickness: .277” +/- .001”. Hole is rough edged and is “as molded”
3. Insulator (head side) gasket thickness: 0.019” maximum.
4. Insulator (carb side) gasket thickness: 0.022” maximum.
5. Check for any alterations or worn parts that would allow additional air into engine:
holes, slots, perforations, spacers, loose bolts, warped flanges etc. Any evidence of
air leaking is grounds for disqualification. Intake:
Valve Springs:
Valve springs will be stock Honda springs and will not be altered in any way.
A. Wire diameter: 0.064” maximum
B. Outside diameter of spring: 0.588” maximum
C. Number of coils: 6
D. Spring pressure: 11 LBS maximum at 0.514”
E. Stacked length will be: 0.652” maximum
Rocker Arms – Push Rods – Studs:
Rocker arms will be stock Honda and will not be altered in any way. Rocker arm
studs will be stock Honda. They or their mounting position may not be altered in any
manner. No heli-coiling of mounting holes. No bending of studs. Push rods will be
stock Honda and will not be altered in any way.
Push rod length is 2.774” +/-.002”
Recommendations:
1. Drain fuel from carburetor after every event. This prevents pump gas and other
fuel from clogging internal carburetor jets.
2. Do not ‘power rev’ engine on the stand. This only creates excessive wear on the
crankshaft key.
3. Inspect clutch key frequently, replace if wear is developing.
SECTION 14: Briggs & Stratton 5HP “Flathead” Engine Specifications
Rules for “Flathead” classes have been stable the past few years as this engine is in
a ‘phase out’ period.
14.1 General Specifications: All components to be OEM Briggs & Stratton or
approved aftermarket components. Gaskets and fasteners are non-tech unless
otherwise specified. Gasket sealer on all machined surfaces is acceptable. Ball and
roller bearings shall be of metallic (magnetic steel) construction (excluding retainers)
and be of conventional design. This includes inner and outer races as well as the balls
and rollers. No other materials allowed.
14.2 Cylinder head requirements:
14.2.1 Machining permitted on the gasket mating surfaces and the top of the post
bosses only. Welding on the cylinder head is prohibited.
14.2.2 Heli-coil repair of spark plug threads in original position permitted, no protrusion
into combustion chamber allowed. Bolt hole diameters .348” maximum. Combustion
chamber depths: piston area .011” minimum, spark plug area .408” minimum, valve
area .300” minimum.
14.2.3 Head gasket material non-tech but must be stock configuration and .043”
minimum thickness.
14.2.4 Eight stock head bolts required.
14.3 Bore and Stroke: 2.613” maximum bore, 2.437 +/- .0l0” stroke. Protrusion of the
piston above the top of the cylinder deck is .005” maximum parallel and inline with the
wrist pin.
14.3.1 LOCAL OPTION: allow protrusion of the piston above the top of the cylinder
deck to .015”
14.4 Carburetor requirements: Stock OEM 5hp carburetor only.
14.4.1 Filter adapter (if utilized) top surface must be flat and .250” maximum thickness
from mounting face. Inside diameter of adapter may be radiused .250” maximum.
14.4.2 No more than one filter adapter gasket may be used, thickness .075” maximum.
14.4.3 One or two carburetor mounting flange gaskets may be used.
14.4.4 Swirl is non-tech.
14.4.5 Throttle shaft washer is non-tech and rubber seal must be in place if OEM
(older carbs). Throttle shaft leading edge .040” minimum, trailing edge .086” maximum.
14.4.6 Butterfly must be unaltered stock with .059” minimum thickness at throttle shaft
mating location. Butterfly screw must be unaltered stock, .322” minimum length.
14.4.7 Except for outside end, needle screw must be unaltered stock with o-ring
and washer present. Jet must have stock recess on backside with no funneling of
hole allowed. Main metering hole diameter .062” maximum. Idle hole diameter .028”
maximum.
14.4.8 Air horn diameter 1.011” maximum. Recess at flange end must be as cast,
.726” maximum diameter.
14.4.9 Carburetor bore, from flange end recess to intersection of air horn diameter,
.695” maximum diameter – must be straight, no tapering, no attempts to modify fuel/
air flow permitted (rifling, dimpling, protrusions etc. not permitted).
14.4.10 Diaphragm cover plate may be faced for proper sealing. Aftermarket
diaphragm of stock configuration permitted. Spring and cup must be unaltered stock.
Long fuel pickup tube may not be brass. Short tube inside diameter .066” maximum.
14.4.11 Breather tube must be removed. Any stock, single hole, domed OEM fuel tank
cap is permitted including those with integral splash shields.
14.5 Valve train: Stock, unaltered breather valve only. Two gaskets permitted. Grommet
and internal foam must be in place. Stock, unaltered, single angle valves only.
Length of flat from seating surface to end of valve .035” minimum. Intake valve angle
30º +/-lº, 1.115” minimum head diameter. Exhaust valve 45º +/- 1º, .990” minimum head
diameter. Stock valve springs and lower retainers required. Springs may be machined
to meet length requirements. Exhaust spring must be used on exhaust valve and may
be used on intake valve. One stock upper retainer may be used on either valve, .058”
maximum lip thickness.
Intake valve spring length 1.240” maximum; .087” maximum wire diameter. Exhaust
valve spring length 1.300 “ minimum,1.500 “ maximum, .088 “ minimum wire diameter;
inside spring diameter .625 “ minimum, .640 “ maximum. Both upper valve chamber
surfaces may be spot faced for valve spring stabilization. Depth and geometry of spot
face non-tech. Stock, single angle valve seats required. Valve seat height to cam
centerline 5.740” minimum, 5.775” maximum. Valve seat may not protrude above
cylinder deck surface.
14.6 Ignition systems: Stock, unaltered coil and coil air vane optional. OEM plug
wire only. Connector and plug boot non-tech. Resistance from spark plug wire to
ground is 2,000 ohms minimum, 5,000 ohms maximum. Flywheel must be specifically
designed for Briggs & Stratton 5HP motors: stock or aftermarket billet alumimum
flywheel allowed. Flywheel weight 4 pounds minimum. For safety reasons, NKA highly
suggests tracks/series mandate an SFI approved flywheel such as the ARC 6620.
Flywheel coating of any type is prohibited. Revolving or adjustable flywheel screens
are prohibited. Flywheel key is optional and non-tech.
14.7 Piston requirements: Length from top of piston to top of wrist pin bore .925”
minimum. (Decking of piston permitted to adjust pop up within the .925” min.) Wrist pin
outside O.D. .491” maximum, inside diameter .320” maximum, length 1.720” minimum.
14.8 Rings: All three required.
14.8.1 Width of the top two rings minimum is 0.090”
14.8.2 Minimum overall thickness of top two rings is 0.058” the minimum height of the
second step is 0.035”
14.8.3 Minimum width of oil ring is 0.070” and the ring groove must be in place.
14.8.4 Thickness of Oil Ring minimum is 0.100” +/-.005”
14.9 Connecting Rod Requirements: Approved commercially available aluminum
connecting rod is permitted. Length from bottom of wrist pin bore to top of crankshaft
journal bore 3.1233” minimum, 3.1333” maximum. Connecting rod bolts and dipper are
non-tech.
14.10 Crankshaft Requirements: Stock crankshaft required. Machining, polishing,
addition of material or otherwise altering of counterweights is prohibited. Stock timing
gear in stock configuration required. Connecting rod journal diameter .990” minimum,
Crankshaft journals may be clearance to .775” minimum diameter to facilitate bearing
removal. Thermal treatment of crankshaft is permitted.
14.11 Camshaft requirements: Camshaft base circle is .770 “diameter maximum.
Lifter material is to be ferrous steel only. Lifter head diameter: .982”minimum, 1.005”
maximum, Length 1.606” maximum. Cam profile check must be taken with zero (0)
valve lash.
Camshaft Profile Limits Lift
Exhaust degrees .050 38º BBDC to 33ºBBDC .100 21ºBBDC to 16ºBBDC .150 2ºBBDC to 3ºABDC .200 21ºABDC to 31ºABDC Max .233 “ maximum .200 76ºBTDC to 65ºBTDC .150 48ºBTDC to 4OºBTDC .100 28ºBTDC to 21ºBTDC .050 10ºBTDC to 4ºBTDC Intake degrees
7ºBTDC to 0ºTDC
10ºATDC to 17ºATDC
.233 “ maximum
43ºBBDC to 33ºBBDC
13ºBBDC to 6ºBBDC
6ºABDC to 13ºABDC
23ºABDC to 31ºABDC
• EZ Spin: start 45º to 60º ABDC
• EZ Spin lift base: .013” minimum, .019” maximum, 30º minimum duration, .001”
maximum drop during duration.
14.12 Block requirements:
14.12.1 Side cover must be stock. Stub for governor may be removed and hole
plugged. Gasket mounting surface of side cover and block may be pin punched.
Block must be unaltered stock with the following exceptions.
14.12.2 The lifter bores may be countersunk to provide lifter head fillet radius
clearance. Any means to raise the bottom of the lifter bore boss is prohibited. Welding
to the block shall be for damage repair or lifter bore reinforcement only and may not
constitute a functional modification.
14.12.3 The cylinder deck may be machined, but cannot extend into the rear fin.
14.12.4 Carburetor and exhaust pipe mounting surfaces must be unaltered stock.
Alterations to inside surfaces of intake and exhaust ports are allowed so long as the
intake port will not accept an .880” diameter No-Go plug gage and the exhaust port
will not accept a 1.005” diameter No-Go plug gage. No addition of material is allowed.
No additional holes may exist in the intake and/or exhaust ports. No alterations on the
underside of the valve seats are allowed. Cylinder sleeve, if present, shall be ferrous
material and uncoated.
14.13 Briggs 5 hp Jr. Restrictor Plates: Flat style only with sharp edge. No beveled
or swaged holes. Maximum hole diameter is as follows; Purple = .425”, Turquoise =
.500” and Gold = .575”.
Popular 5hp Flathead Classes (class name: suggested weight range,
ages, and special notes).
All classes run methanol fuel, and are subject to “pump-around” or other inspections
to assure legality of fuel.
•Rookie: 230-250 lbs., 5-8, use .425” (purple) carburetor restrictor plate.
•Junior 1: 230-250 lbs., 8-10, use .425” (purple)
•Junior 2: 250-270 lbs., 10-12, use .500” (turquoise) carburetor restrictor plate.
•Junior 3: 280-310 lbs., 13-15, use .575” (gold) carburetor restrictor plate.
•Senior-Masters: 330-400 lbs., 15+, Masters typically age 35+ with local option of
SECTION 15A: Stock OHV 200 Engine Specifications
The OHV 200 class was formerly known as “clone”. If your track/series requires
additional clarifications or rules for these classes, please contact NKA for further
assistance.
15.1A Current Approved engines: OHV engines generally referred to as Clones
with a maximum displacement of 200 cc’s. (Current legal engines include the Lifan,
Grey Hound, Harbor Freight Blue, Yellow, Jaing Dong, Yamakoyo, Blue Max &
Ducar. However, these names/colors change periodically as new shipments come to
suppliers.)
15.2A Engine Components
15.2.1A All OHV200 components from approved engines must be original OEM items
in their stock state unless otherwise specified. Honda GX200 parts and components
are NOT LEGAL in the OHV200 class except where specifically noted.
Whenever possible, no-go gauges will be used to determine legality. Tolerances:
when comparing OEM parts, a +/-.005” tolerance is permitted unless otherwise noted.
15.2.2A Removal of unnecessary OEM items such as exhaust system, air cleaner,
fuel tank, governor, low oil sensor, etc is permitted.
15.2.3A Welding or epoxy repair permitted to the block and side cover. Repair may
not be a functional modification (performance enhancing) of the OEM part.
15.2.4A Decking of the block is permitted. No pop-up of the piston is allowed (refer to
rule 15.7.1A)
15.2.5A Deburring of excessive flash is allowed but not to alter OEM specification or
appearance.
15.3A General Exhaust Rules: Silencer must be supported by clamped on brace.
No welding of brace to silencer or pipe. Silencer must be able to be removed for
inspection. No aftermarket coatings of any type on pipe or silencer. Header wrap
required for safety reasons. Gasket and/or silicone allowed to seal header pipe to
head. Pipes must be double-nutted or safety wired on at least one stud.
15.3.1A Local Options: are open to the discretion of track/series for exhaust systems.
15.3.2A “Mini” (aka “weenie”) Pipe Option:
15.3.2.1A Mini pipe must be round .750” OD steel tubing & constant diameter for entire
length of pipe. (No multi stage)
15.3.2.2A Entire length not to exceed 15 inches in length & 10 inches minimum length
including silencer.
15.3.2.3A Pipe should have threaded fitting at the end of pipe to screw RLV B-91 mini
silencer into it (no welding). Silencer should have all baffle plates inside and be stock
as supplied from mfg. No grinding of inside of silencer. ID .685 +/-.005
15.3.2.4A Outside baffle holes .1285” ID max. (use no-go pin gauge) Internal baffle
holes .965” ID max. (use no-go pin gauge)
15.3.3A Open Pipe Option:
15.3.3.1A Header pipe must be of continuous length from flange to end of pipe. (no
multi stage)
15.3.3.2A Maximum length 24 inches-measured through inside of pipe w/.250 wide
tape measure. Remove silencer and pull tape measure tight. If any portion of the
length of pipe is below 24 inches--pipe is legal.
15.3.3.3A Pipe cannot extend past rear bumper including silencer.
15.3.3.4A Ceramic coatings permitted on pipe only. Header wrap and brace required.
15.3.3.5A Studs on exhaust may be replaced with regular threaded bolts of equal
diameter and must be safety wired.
15.3.3.6A Silencer RLV 4104 or RLV 8-91 is mandatory with all baffle plates on inside
and be as supplied from manufacture. Baffle holes: Outside baffle holes .1285” ID
max. (use no-go pin gauge) Internal baffle holes .965” ID max. (use no-go pin gauge)
15.3.3.7A No “Loop” Pipes.
15.4A Fuel & Fuel Tanks:
15.4.1A Fuel: All “Stock” Clone classes use 87-octane pump gas. Most tracks/series
have spec 87 fuel available or name an approved location to buy fuel.
15.4.2A LOCAL OPTION: Methanol for all OHV200 classes. *NKA is strongly
considering making methanol mandatory for all OHV200 classes in 2015. Methanol is
safer, easy to tech, consistent, and cleaner burning.
15.4.3A Floor mounted fuel tanks are required. OEM tank must be removed from the
engine. Any pulse type fuel pump permitted and can be pulsed from the crankcase,
side cover or valve cover.
15.5A Clutches: Stamped steel drum shoe type clutches only, No machined Billet
drums allowed. No disc clutches allowed.
15.5.1A Local Option: Open Clutches at the discretion of the facility, series, or event.
15.6A Carburetor:
15.6.1A STOCK: Huayi or Rui*ing type carb only. Choke assembly must be in place
and functional. Venturi .615” blade-type No-Go and throttle bore .751” NO-GO.
Throttle shaft is .115” minimum thickness; material is non-tech. Butterfly is .037” min
thickness. Main metering jet and low-speed idle jet are non-tech. (Since the amount
of air flow (throttle bore & Venturi) and fuel type is controlled, inspecting the jet size
is unnecessary). Filter adapter max 1.375” height. Filter is non tech; no “ram air”. Any
pulse type fuel pump permitted and can be pulsed from the crankcase, side cover or
valve cover. Throttle linkage is non-tech.
15.6.1.1A Emulsion Tube: through hole maximum ID of 0.066” no-go can not pass
through. Minimum length is 1.092” and must have 20 holes (top and bottom); hole
diameter is non-tech
15.6.1.2A Black phenolic insulator plate must be ran between carburetor and block.
Plate hole and finish of plate are non-tech, but must maintain OEM shape. Fuel bleed
off slot must be unaltered. Stock thickness must be maintained at .257” minimum.
15.7A Pistons:
15.7.1A STOCK: Standard bore is 2.685”, maximum overbore allowed is 2.700”. Three
ring design and all rings to be intact and functional; all three rings are mandatory. Top
ring must be the chrome face ring and middle ring must be a moly-surfaced ring. All
rings are “square rings”; no alterations of rings are permitted. Aftermarket pistons
and/or sizes up to .25mm (0.010”) over are permitted.
15.7.1.1A The piston is not allowed to be any higher than the deck of the block at
TDC, zero tolerance (zero deck height).
15.7.1.2A No flat top piston allowed, must be dished-OEM w/no modifications.
15.7.1.3A Ring Sizes:
Top ring: .058” +/-.005” height & .090” +/-.005” width.
Middle ring: .058” +/-.005” height & .100” +/-.005” width
Oil expander ring (reference): .095” +/-.005” height & .092” +/-.005” width
15.7.1.4 Top two rings must support themselves in the cylinder when removed from
piston. They cannot fall through cylinder. Bottom ring is a non-tech item regarding
tension. Bottom expander ring & two rail rings, when mounted on piston and rod in
place should support piston in cylinder when inserted upside-down.
15.7.1.4.1A Ring Tension Inspection Procedure:
• Top 2 rings must support themselves without assistance in cylinder.
• Each of the top two rings should be placed, individually, approx. one inch (1”) down
in cylinder.
• Square ring with piston turned upside down.
• If ring supports itself it is legal. If it falls thru or will not sit square under it’s own
weight it is deemed illegal.”
15.7.1.5A Piston Length: 1.935” max, 1.910” minimum. .580” max top of wristpin
hole to top of piston as measuered with a dial caliper.
15.8A Crankshaft: Standard OEM item with stock stroke length of 54mm or 2.126”
(+/-.005”). No alterations permitted. Journal diameter must be between: 1.180”-1.168”.
As a reference, if needed to prove lack of modification, crankshafts minimum weight
would be over 1700grams.
15.8.1A OEM timing gear in OEM position is required.
15.9A Flywheel and Ignition Coil: Ignition coil must be OEM for all classes. Timing
is non-tech. Flywheel key may be altered and is non-tech; key is not required to be
installed. Due to the variations of the OEM keys and keyways they will be non-tech to
allow optimum timing with a minimum of cost.
15.9.1A STOCK Option 1: NKA approves the flywheels listed below only to be used
with “Mini” Pipe exhaust systems (see Rule 15.3.2).
15.9.2A STOCK Option 2: “Open” Exhaust Clone Classes (see Rule 15.3.3A) Approved
Flywheels, with a minimum weight of 3.3 pounds. No modification or removal of “fins”
is allowed:
•
RaceSeng RSP-13-075 & 077 Rev Wheel NF-S1 ™
•
ARC-6619 flywheel ™
•
ARC-6618 flywheel ™
•
Dyno PVL 211-900 flywheel ™
•
King Wheel Billet Steel DJ-168F-16200-A ™
•
King Billet Aluminum Slipstream Flywheel ™
Any other flywheel should be submitted for evaluation and approval. “Local Option” is
allowed to limit this to a single make of any of the above flywheels if necessary.
15.10A Cylinder Head:
15.10.1A Valve seats can have up to three angles as cut by the manufacturer:
60-degrees and/or 45-degrees only with a top angle relief of 30-degrees. No porting,
grinding or matching allowed to the ports or combustion chamber. No angle milling of
head. Measurement taken from gasket surface: depth check to combustion chamber
floor cannot vary more than .005” in any direction.
Minimum combustion chamber volume when mounted on engine @ TDC is 26.5
cc’s. This is to be done after the event and when the engine has cooled down to a
reasonable temperature. Note: Head gasket required, but thickness is non-tech and
can be either steel or aluminum. Spec on thickness is non-tech to allow competitors
to alter chamber volume to achieve the 26.5 cc minimum, which some engines fall
short of from the factory.
15.10.2A Head Dimensions:
•
REFERENCE: Approximate Head Thickness: 2.910” +/-.005” (non-tech item)
•
Intake Port: .865” +/-.005”
•
Exhaust Port: .865” +/-.005”
•
Intake Seat: .897” no-go gauge
•
Exhaust Seat: .862” no-go gauge
15.10.3A Port Depth: Measured Top of Valve Seat to Port Floor (+/-.010”):
Intake: .844” Exhaust: .812”
15.11A Valve Train:
15.11.1A Valves: Steel or Stainless Steel valves with 45° angle only and no lightening
or polishing. Polishing or sandblasting of valve stem up to port entrance is allowed;
however, polishing of whole valve is illegal. Cannot be visible above the valve guide.
15.11.1.1A Valve Dimensions:
•
Intake valve OD: .980” minimum.
•
Exhaust valve OD .937” minimum.
•
Intake valve length: 2.515” +/-.010”
•
Exhaust valve length: 2.455” +/-.010”
•
Valve Stem Diameter: .213” minimum
•
Minimum valve weight: 21 grams
15.11.2A Rocker Arms: 1:1 ratio rocker arms only. Rocker arms must be steel and are
subject to magnetic test.
15.11.3A Valve Springs:
•
Maximum Length: 1.225”
•
Maximum Outside Diameter: 0.790”
•
Maximum Inside Diameter: 0.650”
•
Maximum Coil Diameter: 0.071”
•
Number of Coils: 4
•
Spring Shims are allowed, must maintain .815” height check including shims.
•
Springs must be made of a magnetic material.
•
NKA retains the right to use the weight as another means of proving a spring’s
legality.
•
NKA retains the right to use the “Spring Coil Check” with a .250” ground tool
steel as no-go gauge
Install height .815”; check with must go gauge .815” with retainer in place. Gauge
must go in both directions with retainers in place as raced.
Upper seals optional, seals may be used on both intake and exhaust: maximum width
thickness of .027”.
Lash caps on exhaust valve only. Intake retainer minimum thickness .225” & exhaust
retainer .250”. Length is .205” +/-.005”. Material must be magnetic.
Inside diameter of valve seats: Intake .897” no-go and exhaust .862” no-go.
Top of the valve cannot be below floor of combustion chamber (can not “sink” the
valves).
15.11.4A Pushrod Length: 5.275” +/-.010”
15.11.5A Lifters
•
Length: 1.360” +/-.010”
•
Outside Diameter: .930” maximum
15.12A Camshaft Requirements: Stock appearing camshaft cores only with the ezspin assembly un-altered and in stock condition.
15.12.1A STOCK: Cam lobe base circle diameter min/max is .860” - .875”. (Remove
taken from pushrod).
15.12.1.2A Duration taken from pushrod. Intake duration of 217/222 degrees at .050
lift and 84/88 degrees at .200 lift. Exhaust duration of 220/224 degrees at .050” lift
and 95/99 degrees at .200” lift (The +/- 2 degree range allows for wear and engine/
gauging variations).
15.12.1.3A Intake lift at pushrod is .215”-.225”. Exhaust lift at pushrod is .222”-.232”.
15.12.1.4A Intake lift at retainer .238” max. Exhaust lift at retainer is .242” max. Lift
is measured off top of retainer at zero lash. Preload the rocker .001”, then re-zero
indicator, and take reading.
15.13A Fasteners: Non-tech, but must retain their original factory size. Heli-coils,
studs, etc allowed for repair purposes. Solid dow pins allowed.
15.14A Gaskets & Sealer: Gaskets must be OEM configuration and are non-tech and
sealer may be applied unless otherwise specified. No Sealers Allowed on Intake or
Carburetor side!
15.14.1A Crankcase gaskets: multiple gaskets and/or sealer allowed.
15.14.2A Non-performance enhancing marking, “engraving”, sanding or other minor
modifications to gasket mating surfaces to improve/enhance sealing capabilities is
allowed.
15.15A Bearings: Crankshaft bearings shall be of metallic (magnetic steel) construction
(excluding retainers) and be of conventional design and stock appearing and the same
dimensions as the OEM bearings. This includes inner and outer races as well as the
balls and rollers. No other materials allowed.
15.16A Coatings & Polishing: All internal parts, including carburetor and head cannot
be coated, tumbled, or polished.
15.17A Crankcase Breathers: are to be routed internally through the valve cover as
originally intended in OEM configuration. No additional breathers allowed.
15.18A Blower Housing Assembly: Pull starter must be present and remain stock.
Angle of installation is non-tech.
15.19A Air Filter Adapter: maximum length is 1.375”. Loss of filter during event is not
grounds for disqualification.
15.20A Rod: Billet rods are NOT LEGAL. Honing is allowed but must maintain factory
defined edge.
15.20.1A Rod & Wrist Pin Dimensions:
•
Rod length: 2.365” +/-.010”
•
Rod Minimum Weight: 125g reference
•
Wrist pin inside diameter: .555” maximum
•
Wrist pin outside diameter: .707” +/-.005”
•
Wrist pin length: 2.110” +/-.010”
15.21A Claimer Rule: Optional at the discretion of the Local Track/Series.
15.22A Restrictor Plates: Available restrictor plates, checked with blade-type NO-GO
gauge:
•
Blue: .550”
•
Purple: .500”
•
Green: .425”
•
Red: .375”
Popular OHV200 Classes (class name: suggested weight range, ages, and special
notes).
Junior 1: 230-260 lbs., 8-12.
Junior 2: 270-310 lbs., 13-15.
Senior-Masters: 330-400 lbs., 15+, Masters typically age 35+ with local option of driver
weighing over 200 lbs. allowed.
SECTION 16: BRIGGS ANIMAL ENGINE SPECIFICATIONS
All components to be OEM unless otherwise specified. Gaskets and fasteners non-tech
unless otherwise specified. Gasket sealer acceptable on all machined surfaces unless
otherwise specified. All parts to be stock appearing and are subject to be compared to
a known stock OEM part.
16.1 Blocks: to be OEM and can be repaired for broken rod or other damage providing
the repair cannot be considered a performance enhancement. Ball and roller bearings
shall be of metallic (magnetic steel) construction (excluding retainers) and be of
conventional design. This includes inner and outer races as well as the balls and
rollers. No other materials allowed. The repair of both coil post is allowed.
16.2 Piston Pop Up: .005” max. (Machining of block deck surface allowed to adjust
pop up.) When measuring piston pop-up, it should be accomplished with bar stock on
parallel with the piston wrist pin and, using a dial indicator check the piston pop-up
in this area. Then without moving the dial indicator rotate the bar 90 degrees on the
centerline of the piston and check the popup it should not exceed 0.005”.
16.3 Maximum Cylinder Bore: is 2.725”, which provides for approx. .035” over bore.
16.4 Crankshafts: OEM only with stock factory timing gear. No modifications allowed.
Stroke is 2.204” max and crankpin journal diameter min/max is 1.094” - 1.100”
16.5 Connecting Rod: Any aluminum connecting rod is permitted. (insert bearing
optional) Length from bottom of wrist pin bore to top of crankshaft journal bore
2.419” “ minimum, 2.429“ maximum. Connecting rod bolts are non-tech. Rod
grinding/”clearancing” is acceptable providing that it is in an area that needs clearance.
Oil hole diameter non-tech.
16.6 Pistons: OEM or Burris pistons only. Length from top of piston to top of wrist pin
bore .655” minimum. Minimum overall piston length is 1.762”.
16.7 Rings: Three rings are mandatory. Compression (top) ring to have chamfer (or
dot) facing up. Scraper (2nd) ring to have the inside chamfer down and dot up. Rings
must be in one piece when removed from block. Minimum width top two rings .095”.
Thickness top two rings .059”- .064”. Oil ring minimum width .065”, ring groove must be
present. Expander ring must be installed. Oil ring thickness .098” - .102”.
16.8 Wrist Pin: Must be magnetic steel. .624” to .626” OD, .438” max ID and 1.901”
min length.
16.9 Crankcase Side Cover: Side-Cover must remain stock OEM item.
16.10 Cylinder Head: Stock OEM cylinder head part #555635. Machining of gasket
surface only allowed. No grinding/machining of ports allowed. Depth of head at shallow
part of head .011” min. The measurement on the shallow side of the combustion
chamber will be taken with a depth gauge on the push rod side of an imaginary line
drawn from dowel pin to dowel pin on valve side of the dowel. It will also be taken over
the spark plug area. The rest of the recess area in the head has no depth dimension,
but the recess must remain visible. Depth at floor of head .319” min. Depth to top of
valve seat is .360” max. Head thickness measured from head gasket surface to head
plate gasket surface is 2.420”. Head thickness to be checked in four places through
the valve guides and the push rod holes with gauge. Width of combustion chamber at
the widest part across the valve seats area checked with a 2.640” NO GO at a depth
of 0.200” in the combustion chamber.
16.11 Valve Seats: To be one angle only. Seats are non-tech and be stock appearing.
Intake seat inside diameter, .966” GO - .972” No Go. Exhaust seat inside diameter,
.844” GO - .850” No Go. Exhaust and intake seat 45-degree angle.
16.12 Ports: To have stock configuration. No porting or modifications of any kind
allowed. Intake inlet: .918 No Go when checking 90 degrees to stud pattern No Go
will be straight, when checking in line with stud pattern No Go will set on floor port
at bottom and stop at upper edge of port on top. 0.864” No Go cannot touch the
valve guide of the intake port. .860”. Plug gauge will be used as a visual check of the
eyebrow area this is not a No Go but a visual assist tool. Exhaust Outlet: .980 No Go.
16.13 Valve Guides: Valve guides non-tech and to be stock appearing. Maximum
depth from cylinder gasket surface to top of valve guide is 1.255.
16.14 Head Gasket: OEM or after market head gaskets are allowed. No aluminum or
copper head gaskets allowed. .042” Min. thickness measured in four places between
head bolts. Measurements to be made with micrometers from inside of gasket.
16.15 Cylinder Head Plate: Must be OEM item. Cylinder head plate gasket must be
stock configuration .055” maximum thickness.
16.13 Rocker Arm Studs: To be stock factory item.
16.14 Rocker Arm Pivot Ball: Stock factory item. Min/max diameter to be .590” .610”.
16.15 Push Rod: Stock factory item. Min/max diameter is .185” - .190”. Min/max length
is 5.638” - 5.656”.
16.16 Rocker Arms: Must be stock as from the factory. Minimum overall length is
2.865”.
16.17 Valve Spring Retainers: Stock OEM item. Min/max thickness is .055” - .075”.
16.18 Camshaft: All cam profile readings must be taken with zero valve lash and
degree wheel at top dead center (TDC) of compression stroke. Readings shall be
measured from push rods. Set dial indicator at zero and do not reset during the profile
process. Only OEM camshaft cores are permitted: part numbers 555532 and 555584.
Lobes may be ground, but not to exceed .870 base circle. Mechanical compression
relief non-tech. Camshaft lobes must remain flat and of original width. Maximum valve
lift of 0.255” taken directly off the valve retainer at zero valve lash. Place dial indicator
on valve retainer then tighten ball rocker till you see indicator move 0.001” to 0.002”
this will assure that all the lash is taken out of the valve. Set dial indicator to zero and
then check lift. When checking the lift off the valve retainer the only dial indicator holder
that will be used is three-leg holder.
Camshaft Profile Limits
Intake Degrees
18 to 13 BTDC
0 TDC to 4 ATDC
16 to 20 ATDC
33 to 37 ATDC
42 to 46 ATDC
53 to 57 ATDC
67 to 71 ATDC
Min. Lift
Max. Lift
39 to 35 BBDC
25 to 21 BBDC
15 to 11 BBDC
5 to 1 BBDC
12 to 16 ABDC
28 to 32 ABDC
44 to 49 ABDC
Lift
0.020
0.050
0.100
0.150
0.175
0.200
0.225
0.252
0.257
0.225
0.200
0.175
0.150
0.100
0.050
0.020
Exhaust Degrees
61 to 56 BBDC
44 to 40 BBDC
27 to 23 BBDC
11 to 7 BBDC
1 BBDC to 3 ABDC
10 to 14 ABDC
24 to 28 ABDC
Min. Lift
Max. Lift
78 to 74 BTDC
64 to 60 BTDC
53 to 49 BTDC
43 to 39 BTDC
27 to 23 BTDC
10 to 6 BTDC
5 to 10 ATDC
16.19 Valves: Stock valves only and to be one angle. Valves may not be polished or
lightened. If working area (that portion of the valve stem translating with the valve guide
area) of valve stem is cleaned, no material may be removed, such as linear grooves,
cross-hatching, etc. Minimum intake and exhaust valve length 3.250”.
16.19.1 Intake Valve: 45 degree seat face. Valve head min/max diameter is 1.055” 1.065”. Depth of dish in valve .099” - .119”.
16.19.2 Exhaust Valve: 45 degree seat face. Valve head min/max diameter is .935” .945”. Depth of dish valve .084” - .104”.
16.20 Intake and Exhaust Spring: Maximum spring length is .930”. Min/max wire
diameter .103” - .107”, measured in three places on spring. Inside diameter of spring
.615” minimum, .635” maximum. Must be stock appearing and have 4/4.5 coils.
16.21 Valve Lifter: Stock OEM lifter. Head of lifter to have a min/max diameter of .820”
- .860”. Min/max length of lifter 1.515” - 1.525”.
16.22 Valve Cover: Stock OEM valve cover, that includes the breather hole for the
tube that runs to the catch can (no threading of hole allowed).
16.23 Intake Manifold: Stock OEM intake manifold only. No modifications allowed
except machining of gasket surface is permitted to meet rule specs. The gasket surface must remain flat for proper gasket seal the intake to head. The intake carburetor
mounting holes may be drilled out to 0.328” max, and the width of the intake to carb
slotted hole will be checked with the same max dia. Min/max length 1.740” - 1.760.
Inside diameter min/max .885” - .905”. Intake to block max gasket thickness .070”.
16.24 Carburetor: “PZ Model 22” only. OEM factory carburetor only. Parts inside the
float bowl or that can be removed through the float bowl are non-tech. Any 1/4” bolts
may be used to attach carburetor to intake. No studs allowed. Carb to intake sealer is
by O-Ring only. No sealer allowed. Air must enter carb at air horn only. Choke must
be stock appearing as from factory except choke maybe secured in open position.
Adapter will be allowed on end of fuel inlet of carburetor for attachment of 1/4” fuel
line.
16.24.1 Throttle Bore: Max diameter is .874” must be as cast.
16.24.2 Choke Bore: Max diameter is 1.149” and must be as cast.
16.24.3 Venturi: Vertical max width is .792”, this measurement shall be made with
the No Go held parallel to the bore of the carburetor. Horizontal max width is .615”
for top and bottom of Venturi (widest part), and .602” max will be the horizontal
check for the narrowest part of Venturi, and this No Go may not enter slide area. Air
pick off hole maximum diameter .061”.
16.24.4 Throttle Slide: OEM item only. Minimum length top edge of slide to deepest
part of cut away 1.142”. Alternate method is to check the depth of the cut away on
the slide by placing it on a flat surface and attempting to run a .075” No Go pin into
the .074” max cut away.
16.24.5 Main Jet Metering Rod: Min/max length is 1.677” to 1.692”. Taper on needle
must not be less than .070” at .500” from the tip.
16.25 Air Filter: Air filter is optional and any air cleaner permitted. If air filter is used
it must be installed directly to carb and no filter adapter is allowed. Filter may not be
used as an air ram and must filter from all areas as raced. Any open areas in filter
must be covered with a filter sock.
16.26 Fuel Pump: Pulse-type fuel pumps allowed. Fuel pump to be externally
mounted and has to be pulsed only from the crankcase upper oil fill cap.
16.27 Ignition: If “JR” flywheel is used, the coil must be stock OEM coil part #
557040 to be utilized in unaltered form. No slotting of mounting holes or machining of
attaching bolts is permitted. There must be resistance from ground to the plug wire.
Spark Plug Connector must be stock factory type. Rubber plug boot allowed. Min
weight 4 lb. 8 oz.
16.28 Ignition: If “PVL” flywheel is used the “PVL” coil must be utilized in unaltered
form. No slotting of mounting holes or machining of attaching bolts is permitted. There
must be resistance from ground to the plug wire. Spark Plug Connector must be stock
factory type. Min weight 4 lb. 4 oz.
16.29 Flywheel: key, coil air gap, spark plug boot and flywheel nut and washer nontech. Any 14mm commercially allowed.
16.30 Recoil Starter: Non-tech and optional. Any style starter nut is allowed.
16.31 Header and Silencer: Exhaust pipe/header must not extend past rear bumper
(including silencer, where applicable) and have no exposed sharp edges. Header
shall have a maximum length of 24” to be measured in the ID using a .250” wide
tape measure. Measurement to be made with silencer off of pipe and tape tight. If
any part of the pipe is less than maximum the pipe is legal. Loop header pipes not
allowed. Header/exhaust pipe may not protrude inside of exhaust port more than .625”.
Header to be of fixed design and no slippy pipes allowed. No extra tubes or extra holes
allowed except hole for heat sensor probe if sensor is used. All header pipes must be
of continuous length from the flange to end of pipe with stages or butt welds permitted
(no chamber, infusers, or covers of any type allowed on muffler, etc.) A Header support
brace and safety wiring of header bolts or studs is mandatory to assure header bolts
remain tight. It is required that the safety wire wrap around pipe to insure that bolts
remain with pipe in case they are stripped out of block.
16.32 Shrouds and Covers: Engine shroud and covers and control bracket to be
intact and stock appearing. The exception is the control cover, which can be modified
to attach fuel pump (fuel pump must be visible) and throttle bracket also cylinder cover
maybe cut for thermal coupler, intake manifold, and exhaust flange clearance. New
OEM air shield/guard “Part #555680” may replace plastic control cover and control
bracket.
16.33 Engine Seals: The engine will be sealed with two wires one wire will run between
a valve cover bolt and a intake to engine bolt to a the nut side of a carb to intake bolt
the other wire seal will seal the front side of the cover bolt.
16.34 Clutch: Dry clutches only.
Popular Animal Classes (class name: suggested weight range, ages, and
special notes).
All classes run methanol fuel unless noted.
•Rookie: 230-250 lbs., 7-10, use .275” top hole and .375” bottom whole (blue-turquoise)
carburetor restrictor plate.
•Junior 1: 240-270 lbs., 10-12, use .505” (gold) carburetor restrictor.
•Junior 2: 290-320 lbs., 10-12, use .575” (black) carburetor restrictor plate.
•Junior 3: 280-310 lbs., 13-15, use .575” (gold) carburetor restrictor plate.
•Senior-Masters: 330-400 lbs., 15+, Masters typically age 35+ with local option of
SECTION 17: Briggs & Stratton LO 206cc SPECIFICATIONS
NKA suggests all tracks and racers visit the below website page for the latest
specifications on this engine package:
http://www.briggsandstratton.com/engines-racing/news/206%20Crate%20Race%20
Engine%202013%20Rule%20Set%20Released/~/media/Racing/LO%20206%20
4x6%20Book%20-%200113.ashx
Briggs & Stratton LO206 Rules used with permission of Briggs & Stratton Racing.
The LO206 rules set is word-for-word as supplied by Briggs & Stratton.
Introduction to the Briggs & Stratton LO206:
“The 206 engine platform is designed and engineered exclusively for racing. Each engine is
hand-built in Milwaukee, Wisconsin using dedicated tooling and dies to provide a level
of consistency unmatched in the industry today.
The 206 is intended to simplify the steps needed to hit the track and the tech process needed to
ensure a level playing field at the end of the day. In combination with Briggs & Stratton Racing’s
slide restriction system a complete ladder system can be developed by simply changing a
carburetor slide or by a slide and ignition change.
With the base engine the basis for today’s ‘box stock’ classifications, the 206 engine gives
racer’s and tracks the ability to have one engine, from start to finish.
All Briggs & Stratton (B&S) racing engines are manufactured for sanctioned racing only. B&S
does not recommend the products referenced herein to be used for an application outside of
sanctioned racing as serious injury or death could result.
This rule package has been prepared by Briggs & Stratton Racing and is intended to establish
the basis for the technical control of the classes in which the LO206 and LO206
Junior engine is specified. For ALL other regulations, general safety, etc. please refer or contact
your sanctioning body.”
“Unless these rules state that you can do it, you cannont do it.”
LO206 TECH UPDATES:
“Effective 8-20-13
Previous rocker arm minimum length specification - 2.865 inches
Rule update, effective immediately - 2.850 inches
Reason:
The overall tolerance and critical dimensions (center to center, center to push rod
journal, to measurable weight) have not changed but a recent adjustment in the
stamping of our rocker arm has reduced the overall length of the trim “tab.” The trim
“tab” is simply the small gate of material at the very tip of the rocker arm that functions to control the location of the part during the stamping process.
Contact:
David Klaus
Briggs & Stratton Racing
BriggsRacing@basco.com
3300 N. 124th St.
Wauwatosa, WI 53222”
TECH LEVELS
Different scenarios and events may dictate a different “Tech Level” to be performed
at each venue. This is left to the discretion of the local Technical Director; if he/she
feels it’s necessary to “send engines home in a box” they can. However, most events
(especially at the local level) do not deem this level of post-race technical inspection
necessary. For that reason, NKA has developed the below listed “Level 1, 2, 3”
inspection criteria suggestions for both 2-cycle and 4-cycle.
Level 1 Tech (2-cycle):
1. Airbox: inspect with No-Go gauge inner diameter of airbox tubes, inspect with
length gauge the length of the airbox tubes. Remove the airbox to assure filter or inlet
is legal (no velocity stacking or ram-air devices installed.
2. Carburetor: inspect inlet end of the Venturi with appropriate No-Go gauge.
3. Fuel: check with Digatron meter.
4. Exhaust System: if outlet hole is a regulated size (such as Yamaha Supercan
classes), inspect with appropriate No-Go gauge(s). If necessary and possible, remove
the end cap of the Supercan/Pipe and inspect internal holes with appropriate No-Go
gauge for legality.
5. Exhaust System Length (TAG): if a specified length is required, measure the length
as installed/raced per the rule. This can be done easily and accurately with a flexible,
narrow, steel, tape measure.
1. Any and/or all of the Level 1 technical inspection criteria can be performed.
2. Carburetor: remove from engine and inspect inner Venturi diameter with No-Go
gauge. Remove external panels/covers to inspect if all appropriate internal parts are
present (screens, gaskets, diaphragms, etc.).
3. Inspect inlet tract length (piston ports) to appropriate rules.
4. Cylinder Head CC: remove engine from chassis and allow to cool to or near
ambient temperature. Follow appropriate guidelines to inspect cylinder head volume:
assure piston is near TDC, install LAD plug (if required by rule), fill head with just
under specified amount of Marvel Mystery Oil (MMO), complete filling with MMO to
regulated amount in cubic centimeters for that engine, by hand rotate piston to TDC.
Any spillage of MMO is a disqualification.
5. Port Timing (Piston Port Engines): with appropriate LAD tool, check Port Timing by
removing head and installing depth gauge.
6. Squish (TAG): using .060” solder, “squish” solder between piston and top of cylinder
head in two places (preferably parallel to wrist pin).
7. Timing/Ignition: visual inspection of appropriate/legal stator, coil, and other ignition
parts. Inspect ignition timing to assure within the legal parameters.
1. Any and/or all of the Level 1 or Level 2 technical inspection criteria can be performed.
2. Remove cylinder: visually and with appropriate measurements inspect for illegal
modifications.
3. Inspect piston for illegal modifications (cutting, chamfering, etc.). Measure piston
for appropriate specifications; remove from connecting rod if needed.
4. Bottom-end Inspection: remove ignition stator, clutch, and other necessary items to
split the crankcase. Measure and visually inspect the crank, rod, cases, and bearings
for illegal/appropriate specifications for specific engine.
5. Weigh rod and crank to assure they confer to class rules/limits.
1. Fuel check
2. Exhaust pipe and silencer check.
3. Carburetor tech: refer to specific engine.
4. Air filter adapter and restrictor plate if required.
5. Check as well as external visual engine checks.
1. Any and all of LEVEL I checks
2. Removal of rocker cover and examination of rocker assembly.
3. Remove one or both springs and perform checks on wire diameter and 10.8 lbs
check and .815 valve spring installed height check.
4. Running lift measured off valve spring retainer.
5. Check as well as external visual engine checks.
1. Any and all LEVEL I AND II checks.
2. Cam duration check.
3. CC check of combustion chamber.
4. Removal of cylinder head to check valve diameters, ports & combustion chamber
and all other head related components.
5. Bore & stroke measurements.
6. Piston pop up check.
7. Removal of piston, rod, crank & other internal components in that area.
8. Camshaft visual inspection along with base circle check.
9. Crankshaft visual inspection along with all related crank measurements.
10. Any remaining parts will be checked at this time, flywheel, crankshaft cover &
bearings, etc. to finalize complete engine tech and confirm that everything conforms
to the rules and are of the proper material.

NKA Rules - National Karting Alliance

Transcription

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