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| 2011 Rules |
CLASSES
1.) KIDDIE KART
Age: 5 thru 7. Minimum Weight: 155 lbs. kart & driver after the race.
Engine: Comet c50/ c 51 unaltered stock. Subject to a $350.00 claim.
2.) ROOKIE BOX STOCK
Age: 7 thru 11. Minimum Weight: 265 lbs. kart & driver after the race.
Engine: Stock 5 hp Briggs & Stratton “Sealed Motor” w/ Restrictor Plate .390” Yellow. Fuel: Alcohol Only. See engine rules. 13t clutch driver only with 55, 56, or 57 tooth rear sprocket only.
3.) BOX STOCK
Age: 7 thru 11. Minimum Weight: 265 lbs. kart & driver after the race.
Engine: Stock 5 hp Briggs & Stratton “Sealed Motor” w/ Restrictor Plate .425” Purple. Fuel: Alcohol Only. See engine rules.
4.) CONTROLLED STOCK/ SPORTSMAN
Ages 12 and up, weight minimum 320 lbs. kart and driver after race.
Engine: Sealed 6.5 h.p. "clone" motor only. Some modifications are allowed. Governor removed H5 timing key, GX140 emulsion tube, main jet non tech, pump gas only, 18 lb. valve springs, 1 to 1.3 valve rocker, RVL header, RVL silencer. All major components must be sealed by an authorized seal center. Please call 715-851-5810 for more info.
5) JUNIOR II
Ages 8 to 12, weight minimum 290 lbs. kart and driver after race.
Engine: Stock 5 HP Briggs & Stratton, with .500 turquoise restrictor plate, or Briggs and Stratton stock animal with .275 top hole and .325 bottom hole turquoise/blue restrictor. Fuel: Alcohol. WKA section 1014.2 Heartland Speedway Regulations.
6.) JUNIOR III
Ages 12 to 15, weight minimum 320 lbs. kart and driver after race.
Engine: Stock WKA Briggs & Stratton Animal, .505 gold restrictor plate or WKA Briggs and Stratton Flat Head with .575 gold restrictor plate. Fuel: Alcohol. WKA Section 1014.4 Heartland Speedway Regulations
7.) WKA PRO ANIMAL
Age: 15 and up. Minimum Weight: 360 lbs. kart & driver after race.
Engine: WKA Briggs & Stratton “Animal Motor” w/ no Restrictor Plate.
Fuel: Alcohol only. See Animal Medium Spec Motor rules.
8.) GSR LAWNMOWER
Click here for a link to the lawnmower rules. The contact number for this class is: Troy Miller, 715-851-1252
ROOKIE BOX STOCK, BOX STOCK, RACING FOR EDUCATION AND CONTROLLED STOCK DIVISIONS
These are local division only. They may or may not be legal at other area race tracks. Any classes not listed are legal at our track. You must have 4 or more karts per class. Please call Ed at 1-715-851-5810 or 1-715-853-8097.
Race Night Procedures
HOT LAPS: 1 session of five minutes each per class. Be on time, on grid,
ready to go or you will miss your chance to hot lap.
DRIVERS MEETING:
All classes at 6:40. All drivers must be present to race.
NATIONAL ANTHEM: At 6:50.
ORDER of Races: To be determined each race night depending on entries/classes.
Heat Races: Start at 7:00 pm. Number of heat races based on number of karts
in each class. Maximum 7 karts per heat race. If 8 or more karts per class, then 2 or more heat races will be run. Starting Position for heat races will be determined by a draw, lower number on the pole. Second heat will be started in reverse order, highest number on the pole. Points from heat races will determine feature or semi-feature race line-ups, and will not count towards season championship points. Number of laps: Kiddie karts and rookie box stock: 6 laps, all other classes 8 laps.
Semi-Feature: Will run after the last heat race. A semi-feature will be run if there are 13 or more karts per class. Starting position will be based on heat race points with the 13th highest starting on the pole. The top 4 finishers will advance to the back of the feature line-up, with the winner starting 9th. Finishing positions will determine points for season championship. Number of laps: All classes 10 laps.
Feature: Will run after the intermission. The top 12 karts from the heat races will run the feature race. The top 8 positions (or 12 positions) will be based on heat race points with the kart with the highest points starting on the pole. Positions 9 thru 12 will be filled by the top 4 finishers of the semi-feature if one is run. Finishing position will determine points for season championship. Number of laps: Kiddie karts: 10 laps, Rookie box stocks and Box stocks: 12 laps, all other classes 15 laps. Points - in the event of a forced early cancellation on the race night: 1.) For any feature race in progress where 1/2 of the laps or more are run, drivers will be given full points per their position at its finish. 2.) All other features not started -drivers will be given equal points for each position. Total points will be added up based on the number of karts in the feature.
Lapped Karts: All lapped karts will always be put and scored as last, unless
they completely pass all the karts in the feature to unlap themselves.
NOTES:
1.) For starting position line-ups: if points are tied, then the kart with the lower draw number will start ahead of the kart with the higher draw number.
2.) All karts must qualify through heat races to run feature or semi-feature races. If there are less than 12 karts, a non-qualified kart may join at the rear of the feature if it meets class rules.
3.) Points go to the driver not with the kart.
4.) Only 1 kart per driver.
5.) 1 Driver can run two classes, but must be pre-registered and pay $20.00 for the first class and $8.00 for the second class.
Race Officials:
RACE DIRECTOR: Shall be official having complete charge of karts while on the
track. Race Director may direct Starter to warn, via pointing furled black flag, competitors of blocking or rough-driving, or may direct removal of competitor from race by presenting black flag, for driving infractions or defective equipment posing a potential safety hazard. Race Director is in direct charge of all officials and race personnel.
GRID STEWARD: Shall be official in charge of the pit and grid areas, including all competitors and other officials in these areas. Grid Steward shall assign pits, direct gridding of events and maintain orderly conduct in these areas.
HEAD FLAGMAN / STARTER: Shall be official in charge of making flag signals to drivers, via contact with Race Director. Head Flagman / Starter and Race
Director shall conduct pre-event drivers meetings to brief competitors regarding
use of flags, special conditions, etc. Head Flagman is in direct charge of Corner Marshals.
CHIEF SCORER: Shall be official in charge of timing and scoring. All official
finishes shall be posted by the chief scorer or designee.
CORNER MARSHALS: Shall be official posted around the course to assist Race
Director and Head Flagman in safe and orderly conduct of the event.
TECHNICAL INSPECTOR: Shall be official in charge of pre- and/or post-race
technical inspections, both specification compliance and general safety. Technical Inspector and Assistants will verify compliance with stated specifications to certify event finishes as official.
OTHER: Certain other officials may be appointed to supervise and assist in the conducting of point events. All officials must report all rule infractions to assigned Race Director.
D - DRIVERS and MINORS RULES:
D - I: It is mandatory for persons under age 18 to have properly executed
(and submitted to the track and on file), a Minor Release Form and other prescribed insurance documentation prior to competing in an event.
D - 2: Minor Drivers: Must satisfactorily demonstrate driving capability to officials when requested to do so.
D - 3: Drivers Competition Age: A driver’s actual age as of January 1st, 2011, shall establish “competition age” for that entire calendar year.
Example: If you are 11 on January 1st and will turn 12 anytime after the first day of the year, you can run the 11 year old classes.
NOTE: Race Director will have final say as to what age group a driver may be best suited to race in.
D - 4: Eligibility to Change: If, during the season, a driver has a birthday that would make him/her old enough to move up to an “older Class”, they have the option to do so at the time of his/her birthday. Any driver that moves up a class cannot move back.
D - 5: Age Requirements: Falsification of a competitor’s age or any information required on the driver application form will subject the driver to disqualification and/or suspension of privileges.
D - 6: Conduct: All drivers shall conduct themselves in an orderly manner.
Physical violence or abuse of any individual (official, participant, spectator, etc.) at “the Kartway” will subject the offender to immediate ejection from the facility and face possible suspension of privileges.
D - 7: Verbal Abuse: Verbal abuse or threats at any individual (official, participant, spectator, etc.) at “the Kartway” will subject the offender to immediate ejection from the facility and face possible suspension of privileges.
D - 8: Prohibited Substances: All participants entering the Kartway 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 facility immediately.
D - 9: Pit Crews: Drivers are responsible for the control and actions of their pit crew members. Unacceptable actions of crew members may subject the driver to penalty or disqualification from an event or suspension of privileges.
D - 10: Penalties: All drivers and/or crew members will not engage in any physical or verbal abuse on the Kartway grounds. Drivers are responsible for their crew members.
1st Offense: Loss of points to date. 4 weeks minimum.
2nd Offense: Loss of points to date. 4 weeks minimum. AND 2 weeks
suspension from the Kartway.
3rd Offense: Loss of all points and race track privileges for the balance of the season.
NOTE: All penalties will be assessed by the race director and tech officials to determine the severity of all penalties.
D - 11: Event Entry: It is mandatory to properly enter a class or classes prior to entering the track for practice, qualifying or events. Failure to do so may result in disqualification for that event and/or suspension of privileges.
D - 12: Restricted Area: All individuals entering the restricted area of a "the Kartway" event must sign and execute all insurance related documents as prescribed for that event. Failure to do so will subject the individual to disqualification and/or suspension of privileges.
G - GENERAL RACING RULES:
G - I: Course Markings: Course markings such as curbs, pylons or other markings so designated by the Race Director must be observed by all drivers at all times. If, in the opinion of the Race Director, a participant is purposely ignoring course markings, the participant will be subject to disqualification from the event and/or suspension of privileges.
G - 2: Sportsmanlike Driving: The spirit and intent of sportsmanlike racing competition is to proceed on the track without touching or endangering the vehicles or participants. Inadvertent contact is a reality of racing, however, if in the judgment of the presiding officials, a participant is bumping, crowding, chopping, blocking or pushing other participants in other than an inadvertent manner, that participant shall be subject to immediate disqualification from the event and possible of privileges. In practice or racing any unsportsmanlike conduct after the checkered flag may result in disqualification and/or suspension of privileges at the discretion of the race director.
G - 3: Lapped Karts: Participants about to be lapped by faster competitors are responsible for being aware of the approaching faster karts and must yield the racing line until the faster karts have passed. Lapped karts will observe the passing BLUE Flag or subject themselves to disqualification. When given the BLUE Flag (or move over flag) karter must move to the TOP of the race track.
G - 4: Stopping on Course: If for any reason a competitor is forced to stop on or near the course during a practice or event, it is the responsibility of the competitor to assist in removal of the kart to a safety zone as quickly as possible. If a competitor is forced to stop on the racing surface during a practice or an event, the competitor must raise both hands to signal approaching competitors that they are immobile.
G - 5: Re-entry to Course: When a competitor leaves the course other than to
a designated pit lane during the course of a practice or event, they will re-enter the racing surface at a point as far away from the racing “line” as possible and may not enter at another point on the course that will provide them any time or distance advantage. Drivers must abide by the directors, the turn marshals or officials in charge.
G - 6: Slowing on the Course: When a kart slows from racing speed on the
course, the driver must signal such to approaching competitors by raising a
hand high enough to be clearly visible from behind. This requirement includes
slowing to enter a pit entrance lane during an event or practice.
G - 7: Impound Area: Karts retiring from an event must weigh in and proceed to the impound area or they will be ineligible for points and/or rewards.
G - 8: Exiting Track: At the completion of the event, all karts exiting the track must proceed to the area designated by the race director or they will be ineligible for points and/or awards.
G - 9: Inspection: The race director or tech director (inspector) may require any competitor to submit to technical and/or safety inspection at any time. Failure to do so may result in loss of all points for all classes run at that event and may result in suspension of privileges. At all GSR events, the winner and other top 5 finishers may be subject to post-race inspection.
G -10: Proper License and Equipment: A competitor shall be deemed improperly entered and subject to disqualification, possible suspension, etc., if
competitor is improperly licensed or equipped to compete in class(es) on track
either in practice or a race event.
G - 11: Meetings: All drivers must attend drivers meetings, any driver
registering late (after registration has closed) will start in the back.
G - 12: Accidents: In the event of an accident on the track, the only people allowed on the track, are track officials and safety personnel.
G - 13: Disqualification and Points: In the event a driver is disqualified from his/her class for unsportsmanlike conduct in the form of physical and/or verbal abuse, that driver may be penalized in the manner that they will have to use that race in his/her respective divisional/combined points.
Example: The driver may not use it as a drop race. If the driver is repeatedly disqualified for any reason they will be unable to use those races as drop races.
G - 14: Yellow flag rule: If a karter brings out a yellow flag for any reason. (Example: kart won’t run, spin out, etc.) Each karter will be given 2 yellows per event. After you are charged with the second yellow, you will go to the pits for that event.
P - PIT RULES:
P - 1: Control of Restricted Areas: The restricted areas of the track requiring pit pass for entrance is under complete control of the assigned officials. The race director may limit the number of persons that can enter this area to a set number per entry. All persons entering this area, whether connected with an entrant or not, are subject to all regulations regarding deportment and behavior and may be ejected from this area by the officials in charge.
P - 2: Insurance Regulations: Persons entering the pit and/or restricted areas must comply with all insurance regulations and registration procedures. Failure to do so or entrance by fraud, deceit, or passage into the area except by designated gate(s) will subject individual to immediate removal from the restricted area and possible suspension of privileges.
P - 3: Fire Safety: The use of open flame devices in the pit or grid area is prohibited. An area away from fuel and/or other flammables should be designated for welding. No smoking is permitted in grid and pump-around areas.
P - 4: Fire Extinguishers: Competitors are required to have a fire extinguisher on hand in the pits. One fire extinguisher per pit is required. This is an insurance and safety issue. These can be purchased inexpensively. The track will provide four or more large fire extinguishers for all racing events.
P - 5: Waste Oil and Fuel: All competitors will provide waste oil and fuel containers at the track and are responsible for their disposal off site. Any competitor or crew member found dumping oil or other hazardous waste will lose
all privileges and will be responsible for proper cleanup.
P - 6: Personal Vehicles: Vehicles for personal transportation, machine or human powered, may be restricted from the restricted/pit area at the discretion of the officials in charge. Skateboards (powered or manual) are specifically prohibited from these areas.
P - 7: Grid Area: No more than one person per kart (besides driver) so designated by officials in charge, may enter grid area. The grid area is the area
which is designated by officials for line up and staging for events or entrance to the track. Entry to the grid is strictly under the control of the race officials and failure to comply with their directives will subject violators to immediate removal from the restricted/pit area and possible suspension of privileges.
P - 8: Pit Area: Cold karts are not allowed to move from area to area under power.
F - FLAG RULES:
F - 1: Green Flag: Used in practice when the track is clear. Used for an event to designate the start or restart of a race and to declare that the track is clear for racing.
F - 2: Yellow Flag: Indicates caution on the track. Do not race back to the caution flag given from the head flagman. Reduce speed. No passing is permitted under yellow flag conditions. Karts are to stay in line and maintain a
close interval with kart directly ahead. When a yellow flag is given by the head
flagman or starter, it designates a full course caution, unless specified at driver’s meeting. When a yellow flag is given by a turn Marshall, it may pertain only to a certain corner on the track. Specific instructions for the event are provided at the driver’s meeting, and shall apply for that event.
F - 3: Red Flag: All competitors are to stop as quickly and safety as possible at the point designated by the race officials. Do not race back to the red flag. Disobeying the red flag will result in immediate disqualification.
F - 4: Black Flags: Rolled Black Flag indicates that you are on the borderline for disqualification. This is a warning of unsportsmanlike conduct, rough driving etc.. Open Black Flag indicates that you have been disqualified for safety apparel, unsafe equipment, unsportsmanlike conduct, rough driving, etc.. The kart must proceed immediately to the pit area or to area designated by officials. Failure to comply with the black flag will result in the competitor not being scored for laps run after the black flag has been displayed. Failure to heed black flag may also result in suspension of privileges.
F - 5: White Flag: Indicates there is one lap to go in the event. Use of the white flag is not mandatory.
F - 6: Checkered Flag: Used in practice to indicate that practice laps are over. Karts should proceed back to the pit area. When given in a race, it is to declare that the event is complete, and drivers are to proceed to the pits or scale/impound/inspection areas. Checkered flag must follow the white flag, if used. (In other words, red or yellow can not be displayed alone after the white flag, but they may be used with the checkered to indicate caution on the track, and under these conditions, racing to the checkered is not permitted.)
F - 7: Black and Checkered Flags: Used to end the event under conditions subject to review and subsequent action by the officials.
F - 8: Special Flags: Special flag rules may apply for certain events and will be explained at pre-race driver’s meeting.
GPP - GENERAL PROTEST PROCEDURES:
Protests are allowed by a participant only under the following guidelines.
GPP - 1: GENERAL: All protests involving specifications legality and driver conduct shall be submitted by a bonafide (legal) entrant from the same class
the protest occurred. Protester may be required to submit to similar inspection procedure as the protested participant. (See section GPP-7).
GPP - 2: WRITTEN: All protests must be in writing and clearly define the offense. You must refer to a specification and/or regulation as contained in the rules book. Refer to page, section and paragraph number as they apply. Protest must be submitted in writing to the Race Director within 30 minutes after completion of the protested event. In the event of a scoring protest, protest must be made within 30 minutes after posting of official results.
GPP - 3: FEE: A $100.00 fee must accompany all written protests. If the protest is upheld, the protest fee will be forfeited. The $100.00 fee will be divided, with $50.00 going to the protested driver and $50.00 going into the overall point fund. If the protest is disallowed, the fee will be returned to the protester.
GPP - 4: DISPUTES: A committee formed of GSR officials and selected karters
will hear all disputes. Officials and/or committee will make every effort possible to resolve any dispute the same day or evening of the protest. In the event the dispute cannot be resolved that day, the Race Director will hold subjected protested component until such time that the protest committee can reach a decision.
GPP - 5: APPEALS: Appeals may be made by members only. All appeals must be in writing and presented to the Race Director. The appeal will be reviewed by
officials and committee at the next kartway scheduled meeting and a decision will be made at that time.
GPP - 6: CLAIMS: Any claims, can only be made by bonafide race entrant from same race and class.
GPP – 7: ENGINES: If your protest involves any engine rules, protester must bring his motor to the tech area. It will be up to the race director and tech personnel if protester engine will also be inspected for protested specification/and or regulation.
S - SAFETY RULES:
S - 1: Head Gear: Full coverage (full face) helmets designed for competitive motorsports use, complying at minimum with Snell Foundation 2000 specifications are mandatory. Helmets meeting SneIl 2010 specifications are highly recommended and will be required in the near future. Helmet must be in good condition and is subject to pre-tech inspection. It is recommended that participant label or letter rear area of helmet with blood type and any special medical information such as specific drug allergies. Helmet must be secured with a strap. Failure to properly secure helmet may result in disqualification. Long hair must be secured with body sock or under helmet.
S - 2: Eye Protection: Eye protection is mandatory, either goggles designed for motorsports use or a full visor integral with helmet is required.
S - 3: Neck Braces: Collar-type, unaltered neck braces designed for motorsports use are mandatory in all classes except Enduro lay-down karts. Loosing a neck brace will cause immediate removal of the competitor from practice or race. At the discretion of the race official in charge, the competitor, having corrected the problem, may resume racing in whatever position he may safely rejoin the event.
S - 4 Driver Apparel:
S - 4-1: Suits: Drivers are required to wear jackets of leather, vinyl or abrasion resistant nylon or equivalent and full length pants to prevent or minimize abrasions. (A specifically designed kart racing suit is highly recommended and may be required in the future.) No sweat pants are allowed.
S - 4-2: Gloves: Gloves are required. (Drivers or abrasion resistant gloves are highly recommended and may be required in the future.) Mechanix or crew gloves should at least be used.
S - 4-3: Misc. Safety: Chest and/or rib protectors are strongly recommended. Socks must be worn. High top shoes are recommended, no sandals or open type
shoes are allowed.
S - 5: Safety Tech: All driver personal safety equipment is subject to pre-race inspection, and is subject to reinspection at any time. Failure to meet safety inspection, at race directors discretion, may result in disqualification.
S - 6: Seats: All laydown-type seasts will have to have an approved guard above the rear disc between the brake and the seat (example: Wolf Plates). Tech will have the final say on this device.
K - KART RULES:
Karts must meet all track and WKA specifications or be subject to
disqualification or suspension of privileges as deemed appropriate by Race Director. All items will be subject to pre-race tech inspection to make sure all karts are safe for competition. All drivers and/or crew members will not engage in any physical or verbal abuse on the kartway grounds.
Drivers are responsible for their crew members.
1st Offense: Loss of points to date. 4 weeks minimum.
2nd Offense: Loss of points to date. 4 weeks minimum AND 2 weeks
suspension from the kartway.
3rd Offense: Loss of all points and race track privileges for the balance of the season.
NOTE: All penalties will be assessed by the race director and/or tech officials to determine the severity.
K - 1: FRAME AND OVERALL DIMENSIONS:
K - 1.1: FRAME:
Of proven safe design, main frame members shall be constructed of nominally round tubing, allowing for normal distortion and elongation near bend radii. Minimum diameter for main frame members is 1.0” and maximum diameter is 1.4”. Minimum tubing wall thickness at 1.0” diameter is .078”. Minimum wall thickness at 1.125” diameter or greater is .060”. Frame material shall be, at minimum, cold-rolled, electric-weld (ERW) steel tubing or material of at least equal strength. Note: Tubular steel construction technology is the only type of frame design method currently considered to be within the spirit and intent of the
rules, for all classes, in all divisions.
K - 1.2: When normally positioned on the kart for racing competition, the entirety of the driver shall be within the specified width and length dimensions of the kart.
K - 1.4: WHEELBASE:
Maximum 43.0”, minimum 40.0”, as measured longitudinally between the true axle centers.
K - 1.5: MINIMUM TREAD WIDTH: 28.0” as measured from outside of one tire to inside of opposite tire laterally.
K - 1.6: OVERALL MAXIMUM WIDTH: 50.0” for all classes.
K - 1.7: OVERALL MAXIMUM LENGTH: 74.0”.
K - 1.8: HEIGHT: Maximum of 26.0”.
K - 1.9: Floor Pan: and seat back shall be of a design that would prevent any portion of driver’s body to pass between these components to the track surface.
K - 1.10: MINIMUM KART WEIGHT:
Dry weight, fully-equipped including single engine: 85 lbs.
K - 1.11: All non-structural weights: added to meet minimum kart/driver weight requirements must be bolted securely to the kart. To secure weights, anything in excess of 7 lbs., it is highly recommended that TWO 5/16” bolts be used. Mounting of weights to nerf bars or rear bumper is prohibited. Driver is not allowed to add any weight to his/her body other than necessary driving apparel and helmet.
K - 1.12: BOLTS: Must be 5/16" dia. or larger and must be cotter keyed or double nutted.
K - 1.12: DRIVER WEIGHT & WEIGH-IN: All drivers are subject to a minimum combined kart/driver weight check prior to events and a mandatory post-race weight check. Points will be awarded to only those satisfactorily completing post-race weight check.
K - 1.13: SUSPENSION: Use of suspension components of any type, including springs, shocks etc., is prohibited.
K - 2: WHEELS:
K - 2.1: WHEELS: Material optional, but must be of proven design capable of maintaining tire bead seal in competition conditions. No “G-rings” or lateral-supported wheels allowed.
K - 2.2: The dish (opening) of the wheels may not be covered in any way. No
hub caps, tape or any other material allowed to plug center of wheel.
K - 2.3: Clip-on wheel balancing weights are not to exceed 1/4 ounce weight each. Additional security is suggested when utilizing stick-on weights. A lack of security is not grounds for disqualification.
K - 2.4: Maximum width on any tire and wheel combination of 10-3/8”.
K - 3: AXLES AND HUBS:
K - 3.1: WHEEL HUBS: Must be constructed of metallic materials.
K - 3.2: WHEEL BEARINGS: Ground-ball or roller-type bearings only. Split race bearings are not acceptable. Wheel bearings must be adjusted so there is no excessive wheel play.
K - 3.3: FRONT AXLE NUTS: Must be cotter-keyed and rear must be safety wired, cotter-keyed or snap-ringed. Self-clamping wheels may utilize snap-rings
instead of nuts. Berry clips are allowed in place of safety wire or cotter pins where applicable.
K - 3.4: The use of castle-type nuts is suggested. Bolts must be keyed in such a manner to prevent any movement of bolt or nut without key removal.
K - 3.5: REAR AXLE ASSEMBLY:
Axles may be solid or tubular of one-piece design. Minimum diameter is 25mm
(25.4mm = 1.0”). Maximum axle diameter is 1.75”. Axles over 1-3/8” diameter must be of a ferrous material, both driving wheels must be locked to the rear axle with a “live” axle design. Snap ring or similar fasteners are required at each end of rear axle. If a shorter axle is used with an extended hub, it may be fastened from the inside with a fastener that does not allow it to move outward. (See 403.4 HUB)
K - 3.6: AXLE WIDTH: Front spindle, axle and rear axle may not protrude beyond of tire or wheel.
K - 4: STEERING:
K - 4.1: Must be of direct, mechanical type. All steering assembly bolts and nuts, including spindle bolts, must be cotter-keyed or safety wired. All bolts will be minimum 14,000 lb. tensile strength and be minimum 1/4” in diameter, and at least Grade 5 or US Mark 3 rating. All rod ends must have universal type swivel joints. Note: Any fastener (nut or bolt, etc.) of a component that would enable movement of or adjustment of spindle(s), such as for castor, camber, etc., must be drilled for and utilize either a cotter pin or safety wire.
K - 4.2: STEERING SHAFT SPECIFICATIONS:
K - 4.2.1: SOLID: Minimum .625” diameter cold-rolled steel, one-piece design. Wheel attachment must be secured with quality nut or cap screw in an axial position with the centerline of the shaft. Welding the steering wheel to the hub or the hub to the upper shaft is not allowed. No shaft extensions are allowed. No cutting or welding of shaft to alter length allowed.
K - 4.2.2: HOLLOW: MinImum .700” diameter steel tubing, one-piece design, with minimum .070” waIl thickness with minimum 5/16” diameter fastener at end. Steering hub (one-piece, not welded) will be secured through the axis with a 5
/16” diameter bolt parallel to the axis point.
K - 4.2.3: TilIer/vertical shaft steering systems are not allowed. NO rack and pinion steering allowed.
K - 4.2.4: STEERING WHEELS: May be completely circular, minimum of 10” diameter and minimum of 3 spoke design, or may be butterfly type with 10” minimum diameter of 4 spoke design with a minimum 5” grip length on each opposing side. (See 404.5)
K - 5: BRAKES:
K - 5.1: All karts must have brakes working in such a manner to at minimum, brake both rear wheels equally and adequately. All bolts and nuts must be cotter-keyed in such a way to prevent the nut from moving. Brake pedal must be secured to the kart with safety wire or cotter keys. No scrub or band type brakes allowed. Master cylinder actuating rod or cable must be .250” diameter steel or equal quality cable, with positive fasteners at each end.
K - 5.2: Hydraulic brake connectors must be tight and free of any visible leaks. All brake lines should be safely routed to prevent any possibility of being rubbed through or pulled loose while kart is in motion.
K - 5.2.1: Since most competition karts have brake pads secured by countersunk bolts, safety wiring is not feasible. Each karter should monitor proper tightness, and use appropriate thread locking substance to prevent loss of this hardware.
K - 5.3: All master cylinder and caliper mounting bolts and master cylinder roll pins are to be cotter-pinned or safety wired in such a manner that they cannot be loosened without removal of the cotter-pins or safety wire. Nylock-style nuts used to hold the brake disk or drum to their hubs is prohibited. Use of steel locking nuts or drilled bolts with castellated nuts, properly pinned, are the only acceptable fastener for disk or drums.
K - 5.4: Traditional type brake components only. No carbon fiber, etc. allowed.
K - 6: DRIVELINE COMPONENTS:
K - 6.1: Clutches are mandatory in all classes.
K - 6.2: All 4-cycle classes MUST use dry-type engine clutch.
K - 6.3: Karts with outboard clutch mounting must have guard to contain clutch in case engine crankshaft breaks. Clutch mounted between engine and seat does not require third bearing or guard.
K - 6.4: CHAIN AND BELT GUARDS: All chain, belt or gear-driven karts must be equipped with a chain, belt or gear guard designed to retain a broken chain, belt or gear. Outboard drive systems will be allowed only if the chain and sprockets are completely enclosed from front, rear, top and outside.
K - 6.5: EXPOSED SPROCKETS: Karts starting a race or practice which are equipped with an axle sprocket not fitted with a drive chain, must provide a device to prevent exposure from any angle, or encircle the unused sprocket with a chain.
K - 6.6: No transmission, gearbox or other device which permits a change of gear/sprocket ratios while the vehicle is in motion is allowed unless otherwise noted for specific classes. Torque converters are prohibited.
K - 6.7: Chain oilers are prohibited.
K - 6.8: CHAIN SIZES: 35 mm is the only acceptable chain size allowed in all
classes.
K - 7: FUEL SYSTEM:
K - 7.1: Fuel tanks (if not stock Briggs & Stratton mounted on engine) must be securely fastened to primary structure/frame/floor-pan of the kart. Fuel tank must be located within main frame rails beneath the steering shaft unless integral part of the engine.
K - 7.2: Maximum of one fuel tank permitted with maximum nine liter capacity. Fuel line will be of adequate length to connect between fuel tank and carburetor. Excessive fuel line will not be allowed.
K - 7.3: Must be constructed of puncture resistant material and have a secure, leak-proof fill closure.
K - 7.4: No pressurized fuel systems are allowed. NO axle or electric fuel pumps allowed. Must be pulse driven fuel pump.
K - 7.5: Fuel lines must be safety-wrapped at all connecting points.
K - 7.6: FUEL: Alcohol / Methanol with maximum of .810 specific gravity. This means no tampering with fuel.
K -8: BODYWORK, Gold Cup Classes:
K - 8.1: CLASS DIFFERENCES: Some classes may have specific bodywork rules differing from general specifications contained in this section.
K - 8.2: All bodywork must be neat in appearance and in good repair.
Bodywork that appears loose and in danger of falling off may subject the entrant to black flag and/or disqualification during the running of the event. Mounting
method open but must be secure and of good workmanship.
K - 8.3: NOSE CONES: Mandatory and must be of a design outlined in diagram. No “scoop” type pointed nose cones. Nose cone must be a minimum of 8” high, and cannot be inclined less than 40 degrees from horizontal. (Blunt style recommended). Nose cone may be wider than front tires, but no more than 1" per side, measured from centerline of front axle, wheels straight ahead. If nose cone is narrower than front tires, no more than 1/2” of the width of either front tire may protrude, (to be checked at the front edge of the tire/nose cone intersection at centerline of front axle, wheels pointed straight ahead). All nose cones must have a tire opening equal to or greater than the tire used. No covering of the side of the tire is allowed. Use of nose cone as floor pan: The bottom of the nose cone can extend back full width to the rear edge of the front tire. Any part of the nose cone behind rear edge of front tire (i.e., used as floor pan) must be within main frame rails.
K - 8.3.1: Nose cone must allow for easy driver ingress, egress and removal from the kart. It may cover foot area up to 3” rearward of both pedals in relaxed position, and must not interfere with driver’s ability to operate pedals.
K - 8.4: STEERING FAIRING: (See 408.4)
A fairing may extent from the nose cone rearward on an angle roughly paralleling the steering shaft. Maximum width of the fairing is 14.0” (cord measurement, not across the rounded surface). No portion of the steering fairing may be located within 3.0” of any part of the steering wheel. The fairing must be mounted with easily bendable tabs or struts. The fairing and/or mounting materials must expose no sharp edges to the driver. Steering fairing, if used, must have 6” clearance between all surrounding bodywork. Fairing may connect to the nose or floor area of kart with a connecting strip not exceeding 6" in width, and must not cover the drivers feet, ankles or legs as viewed from above.
Note: In Junior I, 2, Box and Controlled Stock classes, no fairing is allowed.
K - 8.5: SIDE PANEL/PODS:
Side panels/pods are the body work that extends rearward of the rear edge of the front tire to the rear edge of the rear tire. Side panels or FMK-style pods may be used and must be securely mounted. Side panels (both flat and 90 degree style) must have a rolled or radius edge on the front and rear opening if it protrudes beyond the wheel and tire as presented for pre- or post-race tech, unless attached to a nose cone or rear pod. If flat (vertical) style panels are used, side panel top edges must have a radiused edge. All side panels allowed maximum 1” lower lip. No metallic side panels allowed. NO WINGS ALLOWED.
K - 8.5.1: If 90 degree panels are used, they may not cover any part of the driver's body. 14” maximum height, all areas. Distance from seat to panel: 1” minimum all areas. Minimum opening area forward of rear bumper to rearward edge of front tires is 22” minimum, measured with tires in straight ahead position. Panels may connect to nose cone. The rear tire may be inside bodywork. Pod, panel or nerf bar can be max. 1” per side wider than rear wheel/tire. The max. over all width is 50”. Pods/panels may not extend beyond rear edge of rear tire.
Side Panels/body panels with molded and curved edges minimum distance of 1”
from seat. (See 408.5)
K - 8.6: BELLY PAN:
A full floor or belly pan is allowed providing it is within the area inside of the main frame rails and is no higher than the center of the rear axle. (See 408.6)
K - 8.7: APPLIES TO ALL BODYWORK:
K - 8.7.1: Body components may not be adjustable while the kart is in motion.
K - 8.7.2: Bodywork must accommodate all applicable bumper and nerf bar requirements.
K - 8.7.3: Kart must have a open cockpit area as viewed from above, except for steering column fairing and nose cone as per above provisions.
K - 8.7.4: All bodywork with the exception of the steering column fairing must be a minimum of 6.0” from the steering wheel when the front wheels are in a straight-ahead position. This is to ensure there is adequate driver entry/egress area.
K - 8.8: NUMBERS AND NUMBER PANELS:
Four (4) numbers are to be displayed on the kart, including one at the front center of the kart as viewed from the front, on both sides in a vertical plane between front and rear wheels, and at the rear of the kart as viewed form behind. Number panels must be of adequate size to accept assigned, disposable numbers. Whether paper-type numbers utilized or numbers are painted or decaled on bodywork, they must be readily readable to the scoring and race officiating personnel. No duplicate numbers in the same class. (See page 38)
K - 9: SKIRTING: Any add on skirting material must be flexible and non-metallic.
K - 10: BUMPERS AND NERF BARS: (See 409)
K - 10.1: FRONT BUMPER: Is mandatory and must be constructed of minimum 3/4“ diameter steel tubing with minimum wall thickness of .065”. The top of the upper hoop of the front bumper must be a minimum of 7.75” above the ground as
raced. The upper hoop must be supported in at least two places in the front portion of the bumper by 3/4“ or larger tubing uprights. These uprights shall be within 1/2" of vertical when measured 3.0" down from the top of the upper hoop. Bumper must be supported by two vertical supports. No weights may be attached to front bumper except approved attachment if bumper is enclosed by nose cone.
K -10.2: Front bumper that incorporates pedal mounting points must be either welded to the frame or through-bolted or pinned with safety wire/ cotter pins.
K - 10.3: REAR BUMPER:
Is mandatory and must be constructed of 3/4” minimum diameter steel tubing with minimum wall thickness of .065” and positioned so that: MAX. Height is 7.5” as raced. MIN. Height is no lower than rear axle. MAX. Width is no wider than rear tires.
K - 10.3.1: Full Width Rear Bumper is mandatory and must cover at least 1/2
of rear tire and not to exceed 50.0".
K - 10.3.2: Oil catch cans may not be attached to the rear bumper.
K - 10.4: NERF BARS: (See 409.4)
Nerf bars must be constructed of minimum 3/4" diameter steel tubing with minimum wall thickness of .065” and must be secured by a minimum 1/4” bolt. The overall length of the side nerf bar(s) shall be a minimum of 24.0”, measured
from the back side of the nerf bar closest to the rear tire in a straight line to where it attaches to the kart at the front. Double-high nerf bars are required.
K-11: SEAT: (See 409)
K - 11.1: Sprint-style “bucket” seats only, no lay down seats allowed. Seat must be of one-piece or molded construction, with no “peaks” or add-on sections intended to subvert the seat back height requirements noted below. Seat must securely locate driver laterally and longitudinally. Seat must bolt securely to the frame and not be adjustable while the kart is underway. No portion of the seat may be located rearward of a plane projected vertically from rear of rear axle. Seat height requirements are: 10” minimum ages 8 to 11, 12" minimum ages 12 to 15 and 14" age 16 and up. Seat must be positioned so that driver can see over the steering wheel. NOTE: Measurement is an actual plane from ground plane to center of seat back.
K - 11.2: SEAT ANGLE must conform to: See Fig. 410.2. This check will be made in an “As Raced Condition”; the surface where the kart is placed will be the plane the angles will be referred to.
K - 12: MISCELLANEOUS:
K - 12.1: It is mandatory for all karts to be equipped with a positive acting throttle-return spring.
K - 12.2: Seat belts or other driver restraints are prohibited.
K - 12.3: Drivers may utilize no type of radio communication devices.
K - 12.4: No mirrors of any type allowed.
K - 12.5: On-board data acquisition systems are allowed. Beacon tower must be on the outside of the track, not towards the infield. Ask race director if any questions on this.
K - 12.6: All down loadable data acquisition systems are illegal on race days. All down Ioadable systems must be removed from the kart in their entirety on race days (including main unit, all sensors, and all wires). No beacons are allowed on the race circuit on race days - all divisions.
K - 12.7: Engine swapping to advance position from heats to feature could be
considered a rule violation and could be automatic disqualification. Check with the Tech Director before changing engines.
T - TIRE RULES:
All karts must run our spec tire - Burris SS-33A.
T - 1: Tires will be slicks only.
Note: New karters from out of the area are allowed one race only before having to switch to the track spec tire. Any non-spec tire will have to pass durometer hardness test of 55 or more (harder). A new karter is someone who has not raced at this track in the last year.
TRANSPONDERS:
All karts must have an AMB transponder. We have them for rent if you don’t own one. (Exception to this rule is the kid kart class.)
ENGINE RULES and SPECIFICATIONS
KIDDIE KART Engine Rules:
KK - 5: Engine Specifications:
KK - 5.1: Comer C-5O Box Stock, unaltered, 1.8 HP, fixed jet carb, jet size = 58.475. No Go venturi. All parts “as cast”. Restrictor Plate issued by WKA.
KK - 5.2: Head cc, 6.5cc minimum. Liner and aluminum cylinder “as cast”. Engine is not legal if any metal has been removed to match port opening to aluminum cylinder. Piston 1.210” minimum from bottom ring. All measurements No-Go.
KK - 5.3: Muffler: Exhaust: Stock muffler only. Original manufacturer only. Only two holes. Vertical measurement No Go .110” each hole / Horizontal measurement No Go .475” each hole.
KK - 6: Class Intent: Class intent is very clear. Anyone found not in compliance with above rules, (parents / guardians / pit crew) are subject to disciplinary action. It is not recommended to disqualify 5 to 7 year old drivers.
KK - 15: KIDDIE KARTS:
Note: The primary purpose of the Kiddie Kart class is to serve as a training / educational process to teach and improve driving skills to beginning drivers. Additionally to teach racing safety and race event procedures to children ages 5 to 7 years old. Kiddie Kart training events can be held at local, divisional and national WKA events. They will be worked into the event program as it best suits the officials in charge. If event participant awards are given out they must be of equal value and accomplishment level. All participants are “Winners”.
K - 15.1: Karts must be safety tech’d before being allowed on track.
K - 15.2: Kiddie Kart driver / Parent meeting will be held before event.
K - 15.3: TRAINING Event Format: Training event will be of a 9 lap duration. Event will be from a standing start, two abreast. Line up will be by draw. The training race will proceed under green, barring the need for a yellow or red flag for 3 laps. The yellow flag will be displayed at the beginning of the 4th lap. The field will proceed at reduced speed, single file, and will maintain position for 2 laps. The green flag will be displayed at the beginning of the 6th lap. Green flag conditions will prevail, barring the need for a yellow or red flag, for 4 laps. The training event will be white flagged at the conclusion of the 9th lap. Awards may be given out at the completion of the event. All participants will proceed to the scale / tech compound (or other designated area) for a critique of the event. Official weigh-in is not necessary but may be done for training purposes.
K - 15.4: Specifications:
K - 15.4.1: Chain guard is to completely cover chain when viewed from above.
K - 15.4.2: Chain / Gearing: Comer-219 chain, 10 tooth driver, 89 axle sprocket.
K - 15.4.3: No offset karts. Seat must not be offset beyond outside edge of left frame rail.
K - 15.4.4: Wheelbase: Minimum 29”, maximum 31”.
K - 15.4.5: Width: Front, maximum 40”, as measured to outside of rim/tire (no min.). Rear, minimum 39”, maximum 42”, as measured to outside of rim/tire.
Rear Bumper: Continuous loop shaped with vertical or angled bracing
connecting upper and lower loop rails. Must protect rear tires.
K - 15.4.6: Steering height: maximum 20”.
K - 15.4.6.1: Seat height: ages 8-11 min. 10”, ages 12-15 min. 12".
K - 15.4.7: Side pods or double nerf bars and nose cones are mandatory.
K - 15.4.8: Tires: Open compound. Front size, 4:50-5; Rear 5:50-5 max. Rear tire circumference, maximum 33”.
K - 15.4.9: Official weigh-in is optional.
K - 15.4.10: Additional return spring on carburetor or on foot pedal, required for additional safety.
Rookie Box Stock/Box Stock:
BOX STOCK - Briggs & Stratton Engine:
BS - 1: Stock 5HP Briggs & Stratton Motorsports engine only. All engines must be purchased from an approved seal center, Butch’s Engine Shawano, and Mitchell Motorsports. NO used engines can be sealed. No engines purchased from other than listed above, can be tech'ed or re-sealed. NO rebuilding allowed except by approved Seal Center.
BS - 2: Clutch must be Raytech GE Series or Maxi Torque TT. $60.00 claim
rule on all clutches.
BS - 3: Mandatory pipe and muffler rule. Spec pipe and muffler are required. All competitors MUST run a Robinson MC-1 pipe only and a RVL-8-91 muffler.
Controlled STOCK/Sportsman – Sealed Clone Motor:
CS - 1: All engines must be purchased from an approved seal center, Mitchell Motorsports or Butch’s Engine. No used engines can be sealed. No engine purchased from other than listed above can be tech'ed or re-sealed. Rebuilding by approved seal center only. Engines previously sealed may be rebuilt and resealed by approved seal center only.
CS - 2: Clutch must be Raytech GE Series or Maxi Torque ll. $60.00 claim rule on all clutches.
JR II:
WKA Specs
JR III:
WKA Specs
Pro Animal
WKA Animal 6.5HP:
708.1: SHROUDS & COVERS: Engine shroud and covers and control bracket must be intact and not modified, except control cover which can be modified to attach fuel pump. Taping of flywheel screen allowed. Tape on block disallowed.
Fixed screen must be afixed to shroud cool air intake area. Any bolt utilized to secure sheet metal, shrouding, etc., with the exception of sheet metal secured by the head bolts, may be replaced witha larger diameter bolt(s). Stock kill switch must remain in stock location but may or my not be used.
708.2: HEADER/SILENCER: Exhaust pipe/header must not extend past rear bumper (including silencer, where applicable) and have no exposed sharp edges.
Header shall have a max. length of 24” to be measured in the ID using a 1/4” wide
tape measure. Measurement to be made with muffler 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 so as to alter port configuration for performance gain. Studs allowed for header pipe attachment to block. NOTE: In events where silencing device is MANDATORY (Divisional, National, etc. points event and were required for non-points, local events), use of RLV 8-91 SILENCER IS MANDATORY. Silencer must be utilized as produced, with no modifications or alterations permitted.
708.2.1: Gasket and/or Silicone allowed to seal the header.
708.2.2: Header must be fixed design, NO SIPPY PIPES allowed. No extra tubes or extra holes allowed except hole for heat sensor probe if sensor is used.
708.2.3: All header pipes must be of continuous length from flange to end of pipe with stages or butt welds permitted (no chamber, infusers, or covers of any type allowed on muffler etc.). Silencer must be visible when viewed from any angle. Header tube and silencer only legal parts.
708.2.4: Extra HEAT SHIELD above chain guard is ALLOWED (all classes).
708.2.5: A header support brace and safety wiring of header bolts or studs is MANDATORY to assure header bolts remain tight. It is recommended that the safety wire wrap around pipe to insure that bolts remain with pipe in case they are stripped out of block. Silencer must be tig˙t, secure, and completely intact on the header throughout the entire event. Silencer must be clamped to header tube and no welding of silencer in any area.
708.2.6: Silencer Baffles holes .1285” maximum all baffles.
708.3: AIR FILTER: Any air cleaner permitted. Must be installed directly to the carb. No filter adapter 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. (No open areas allowed.)
708.4: CARBURETOR: PZ Model 15 Carburetor. Only legal carb allowed. Any
1/4” bolts may be used to attach carb to intake. No studs allowed. Carb to intake seal is by O-Ring only. No sealer allowed. Air must enter carb at air horn ONLY. Choke must be as stock as from the factory. Spring can be used to hold choke in position. Must be stock as from the factory. Adapter will be allowed on end of fuel inlet of carburetor for attachment of 1/4” Fuel line.
708.4.1: Maximum throttle bore inside dimension is .874” NO-GO. Must be as cast.
708.4.2: Choke bore: 1.149” No-Go. Must be as cast.
708.4.3: VENTURI: Vertical .792” No-Go Horizontal .615” No-Go. No machining allowed.
708.4.4 Air pick hole Maximum .061” No-Go.
708.4.5: Slide: Minimum length top edge of slide to deepest part of cut away 1.148”. Must be stock as from the factory.
708.5: INTAKE:
708.5.1: Length: 1.740” minimum, 1.760” maximum.
708.5.2: Inside I.D. .905” NO-GO Max. .885” No-GO Min.
708.5.3: INTAKE TO BLOCK GASKET: Thickness .070” max.
708.6: FUEL PUMP: Auxiliary pulse-type fule pump allowed. Fuel pump must be pulsed only from the crankcase upper oil fill cap only. No hoses or tubes to or from intake.
708.7: VALVE COVER: Stock valve cover as from the factory.
708.7.1: Valve cover gasket must meet stock configuration. No sealer allowed.
708.8: ROCKER ARMS: Must be stock as from the factory.
708.8.1: Overall length 2.880” + or - .005”.
708.9: 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 stock factory camshaft cores from Briggs & Stratton are permitted, part numbers 555532 and 555584. Lobes may be ground but not to exceed .870 base circle. Mechanical compression relief is non-tech. Camshaft lobes must remain flat and of original width.
708.9.1: Camshaft Profile Limits
INTAKE EXHAUST
708.10: BALL ROCKER: As stock from the factory.
708.10.1: .600” + or - .010” diameter.
708.11: PUSHROD: As stock from the factory.
708.11.1: .185” - .190” diameter.
708.11.2: Length 5.638” - 5.656”.
708.12: HEAD BOLTS: Stock head bolt must be utilized and four are mandatory.
708.13: HEAD GASKET: Must be of stock configuration.
708.13.1: .049” min. thickness measured in four places between head bolts. Measurement to be made from inside of gasket. Measurement to be made with micrometers.
708.14: CYLINDER HEAD PLATE: Must be stock as from the factory.
708.14.1: Cylinder head plate gasket must be stock configuration. .055” Max thickness.
708.15: ROCKER ARM STUDS: Must be in stock as from the factory.
708.16: VALVES: Stock valves ONLY. Must 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, crosshatching, etc.
708.16.1: INTAKE VALVE: 45 degrees. Intake valve minimum diameter is 1.055” - 1.065”. Depth of dish is valve .99” - .119”.
708.16.2: EXHAUST VALVE: 45 degrees. Exhaust valve minimum diameter .935”- .945”. Depth of dish in valve .084” - .104”.
708.17: VALVE SPRINGS: Stock Briggs & Stratton valve springs and keepers are mandatory. Springs must remain unaltered as supplied from the factory.
708.17.1: INTAKE & EXHAUST SPRING: Maximum valve spring length is .930”.
.103” - .107” wire diameter, measured in three places on spring. Inside diameter of spring .615” minimum, .635” maximum.
708.18: VALVE SPRING RETAINERS: Stock as from factory.
708.18.1: .060” - .070” thickness.
708.19: CYLINDER HEAD: Stock Briggs & Stratton cylinder head part #558, as
shipped from factory, is only configuration approved. No machining of head allowed. No machining of ports allowed.
708.19.1: Depth of head at shallow part of head .016” minimum. Depth at floor of head .324” minimum.
708.19.2: Depth to top of valve seat: .360” max., .340” min.
708.19.3: Bosses on head may be tapped to allow for the attaching of a header brace.
708.20: VALVE SEATS: Must be one angle only on valve seats. Stock Briggs &
Stratton valve seats are mandatory.
708.20.1: Intake seat inside diameter, .966” - .972”.
708.20.2: Exhaust seat inside diameter, .844” - .850”.
708.20.3: Exhaust and intake seast 45 degree angle.
708.21: PORTS: Must have stock configuration. Stock as supplied from factory. No modifications.
708.21.1: 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 of port at bottom and stop at upper edge of port on top.
708.21.2: EXHAUST OUTLET: .980” No-Go.
708.21.3: VALVE GUIDES: Stock valve guides as supplied from the factory. Maximum depth from intake cylinder gasket to surface to top of valve guide is 1.255”.
708.23: DESK/PISTON CLEARANCE: Machining of deck surface is permitted.
Piston pop-up CANNOT exceed .005” above block surface in the center of the piston. When measuring piston pop-up, it should be accomplished with bar stock on a parallel with the piston wrist pin in center of the piston, and using a dial indicator check the piston pop-up in this area.
708.24: CYLINDER BORE: No circular or machined grooving of cylinder is allowed in any position of cylinder.
708.24: Stock cylinder bore is 2.690” and overbore is permitted providing it does not exceed 2.725” (approximately .035” overbore).
708.25: STROKE: Stroke is 2.204” max. Stroke is checked by pushing piston down totake up play of rod clearance. Stroke is checked from bottom dead center (BDC) to top dead center (TDC).
708.26: IGNITION: Briggs & Stratton factory stock coils are MANDATORY and 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. SPART PLUG CONNECTOR must be stock factory type. Rubber plug boot
is allowed. NOTE: Coils may be rechecked for correct ohms after a minimum of 10
minutes.
708.26.1: Resistance from plug wire must be 3,000 ohms MINIMUM and 6,000
ohms MAXIMUM.
708.27: STARTER: Recoil starter may be retained as produced and intact, if recoil is removed, starter cup must also be removed. Any style nut and use of electric starter allowed.
708.28: FLYWHEEL: ONLY stock is permitted. Any flywheel key or NO flywheel key is allowed. No machining, glass beading or sandblasting of flywheel is allowed. Chipped fins because of poor casting is allowable, however, completely broken fins are NOT allowed. Any screen or guard that fully covers the flywheel fins is allowed EXCEPT NO revolving screens. All screens must be bolted to blower housing. Flywheel washer must be stock. Flywheels with plastic fins are not allowed. Briggs Part #555612 is the only legal flywheel.
708.28.1: Weight of flywheel: 32 oz. minimum, 35 oz. maximum.
708.29: CRANKCASE SIDE COVER: Side cover must remain stock.
708.30: CRANKCASE SIDE COVER GASKET: After market gaskets approved,
however, must be the same size and material as stock gasket(s). One or two crankcase gaskets are allowed.
708.31: VALVE LIFTERS: Stock lifter as supplied from factory.
708.31.1: Head of lifter have a min. .820” diameter, .860” diameter max..
708.31.2: Maximum length of lifter 1.525”, 1.515” minimum.
708.32: CONNECTING ROD: Stock connecting rod ONLY. Connecting rod may not be lighter in weight than know stock component. No under-sizing of connecting
rod is permitted, however, rod may be clearanced providing that it is in stock configuration and finish with no “dimpling” or media blasting. Rod ends must be concentric with crankshaft journal and/or wrist pin with no chamfer or breaking of edges.
708.32.1: Stock rod length is 2.419” minimum, 2.429” maximum. Measured from bottom of wrist pin to top of crankshaft journal.
708.32.2: Oil hold opening, new or old style rod, is .185” NO-GO.
708.33: WRIST PIN: Wrist pin must not be altered.
708.33.1: Maximum inside dimension of wrist pin is .414”.
708.33.2: Outside dimension is .624” - .626”.
708.33.2: Minimum length is 1.901”.
708.34: RINGS: Three rings are MANDATORY. Compression, or top ring, chamfer or O must face up, and must remain as manufactured. Scraper ring must be installed with inside chamfer down and O up. Stock oil ring must be installed as from factory. Ends of ring must remain flat. Excessive end gapping of rings not allowed. Rings must conform to all listed factory specifications and be of stock configuration. Known, standards for piston/ring configurations are Briggs & Stratton factory approved parts. No machining of rings allowed. Exception: lapping and end gapping allowed. Rings must be in one piece when removed from block.
708.34.1: Minimum width top two rings .095”.
708.34.2: Thickness top two rings .059” - .064”.
708.34.3: Oil ring minimum width .065”, ring groove must be present. Expanded ring must be installed.
708.34.4: Oil ring thickness .098” - .102”.
708.35: PISTON: Stock, unaltered Briggs & Stratton piston MANDATORY. Wrist
pin hole must not be altered or relocated. Deck above top ring must not be altered. NO machining is allowed on piston. Arrow must point toward flywheel.
708.35.1: From top to piston to wrist pin bore .658” minimum measurement. Check on circlip side of piston.
708.35.2: Minimum piston length is 1.768”.
708.36: CRANKSHAFT: Stock factory crankshaft mandatory. Stock factory timing gear mandatory, and must be installed properly. Lightening, polishing of counter weights, addition of metal or other material is not permitted. Offset crankshafts are not permitted. After-market bearing of non self-aligning type, with or without shield, is permitted. Shims, if used, must be installed as from factory.
708.36.1: Crankshaft journal diameter is 1.094” - 1.100”.
708.37: BLOCK: Must be produced, with no alterations or reworking. Blocks repaired from broken rod damage, are permitted providing tat repair does not constitute a functional modification of original block. No bushings of any kind allowed except for bushings approved by the tech manual. The repair of one
coil post is allowed, as long as the remaining post is factory and unaltered. No KNURLING of guides allowed.
708.38: WELDING: No welding can be done to an engine from the cooling fins upwards. The only welding permitted is to repair damage from a broken rod. 708.39: CLUTCH: Any two or three shoe centrifugal clutch. Claiming rule $150.00 (a competitor may claim another competitor’s clutch for $150.00 to the
race director prior to the feature race). Failure to comply with the claiming rule will cause immediate disqualification of the competitor.