Class Specifications

NOTE: Any class (Except Junior Classes and Amateur) with less than three (3) entries at the first event will be abolished for the remainder of the racing season. In the event that there are two consecutive races with less than three (3) karts, the WBSW Board reserves the right to abolish the class. If running two classes the driver must pay TWO entry fee's.
NOTE: All classes run on Methanol.

JUNIOR SPORTSMAN I LITE - Driver Age: 6-10 yrs
Engine: Briggs & Stratton stock 5hp with .425” restrictor plate {purple}; mixed with animal 3 hole
restrictor plate {purple}
Other: No steering fairing
Weight: 250lbs {minimum}

JUNIOR SPORTSMAN I HEAVY - Driver Age: 6-10 yrs
Engine: Briggs & Stratton stock 5hp with .425” restrictor plate {purple}; mixed with animal 3 hole
restrictor plate {purple}
Other: No steering fairing
Weight: 265lbs {minimum}

JUNIOR SPORTSMAN II LITE - Driver Age: 10-15 years
Engine: Briggs & Stratton stock 5hp with .5” restrictor plate {blue}; mixed with animal
Other: No steering fairing
Weight: 275lbs {minimum}

JUNIOR SPORTSMAN II HEAVY - Driver Age: 10-12 yrs
Engine: Briggs & Stratton stock 5hp with .5” restrictor plate {blue}; mixed with animal
Other: No steering fairing
Weight: 290lbs {minimum}

JUNIOR SPORTSMAN III LITE- Driver Age: 10-15 yrs
Engine: Briggs & Stratton stock 5hp with restrictor plate {gold}; mixed with animal restrictor
plate .505 {gold}
Weight: 300lbs FH; 320lbs animal {minimum}

JUNIOR SPORTSMAN III HEAVY - Driver Age: 10-15 yrs
Engine: Briggs & Stratton stock 5hp with restrictor plate {gold}; mixed with animal restrictor
plate .505 {gold}
Weight: 300lbs FH; 320lbs animal {minimum}

JUNIOR SPORTSMAN CHAMP - Driver Age: 6-10 yrs
Engine: Briggs & Stratton stock 5hp with .5” restrictor plate {blue}.
Weight: 315lbs {minimum}

JUNIOR CHAMP - Driver Age: 10-15 yrs
Engine: Briggs & Stratton stock 5hp; mixed with animal IKF Gold 3 hole
Weight: 345lbs {minimum}

SENIOR CHAMP - Driver Age: 15 +yrs
Engine: Briggs & Stratton stock 5hp; mixed with animal IKF 3 hole
Weight: 425lbs {minimum}

STOCK LITE - Driver Age: 15 +yrs
Engine: Briggs & Stratton stock 5hp.
Weight: 325lbs {minimum}

STOCK MEDIUM- Driver Age: 15 +yrs
Engine: Briggs & Stratton stock 5hp.
Weight: 350lbs {minimum}

STOCK HEAVY - Driver Age: 15 +yrs
Engine: Briggs & Stratton stock 5hp.
Weight: 375lbs {minimum}

LIMITED MODIFIED - Driver Age: 15 +yrs
Engine: Briggs & Stratton stock 5hp {limited} –or- Animal
Weight: 375lbs {minimum} – Animal
Weight: 350lbs {minimum} – Flat Head

FUN CLASS - Driver Age: 15 +yrs Engine: Briggs & Stratton (modified) may run animal with restrictor plate Weight: 350lbs {minimum}

Driver Qualifications

1. CONDUCT:
All drivers shall conduct themselves in an orderly manner. Physical violence or abuse of any individual (official, participant, spectator, etc.) at the site of a WBSW event will subject the offender to immediate ejection from the event site and possible suspension of membership status.

2. VERBAL ABUSE:
Verbal abuse or threats directed toward any individual (official, participant, spectator, etc.) at the site of a WBS event will subject the offender to immediate ejection from the event site and possible suspension of membership status.

3. PROHIBITED SUBSTANCES:
All participants entering the restricted area (pits) of a WBSW 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 the event site immediately.

4. 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 membership privileges.

5. 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 membership privileges. There may be only one (1) entry per class per driver in any WBSW event.

6. AGE REQUIREMENTS:
Falsification of a competitor’s age or any information required on the membership application form will subject the member to disqualification and/or suspension of membership privileges. Members are entirely responsible for supplying accurate information. Age eligibility of all participants will be determined by that participant’s age as of December 31, 2009.

7. RESTRICTED AREA:
All individuals entering the restricted areas of a WBSW event site 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 membership privileges.

8. INSUFFICIENT FUNDS:
Failure to properly pay registration, entry and/or pit fees, including uncollectible checks, may submit individual to disqualification from the event and/or suspension of membership privileges.

COMPETITION PROCEDURAL RULES ALL DIVISIONS

1. SPORTSMANLIKE DRIVING: The spirit and intent of sportsmanlike racing competition is to proceed on the track without touching or endangering the vehicles of fellow 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 for the events and possible suspension of membership privileges.
2. 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 faster karts have passed. Lapped karts will observe the passing (blue) flag or subject themselves to disqualification. Any kart involved in a wreck caused by a lapped kart will retain his position.
3. DIRECTION OF TRAVEL: It is mandatory that all competitors strictly observe the normal direction of travel around a track. Failure to do so, by driving or pushing a kart opposite to normal direction of track unless specifically directed by a race official, will subject participant to disqualification and/or suspension of member privileges.
4. STOPPING ON COURSE: If for any reason a competitor is forced to stop on or near the course during practice or an 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 event, the competitor must raise both hands to signal approaching competitors that they are immobile.
5. SLOWING ON COURSE: When a kart slows from racing speed on 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.
6. DRIVER OF RECORD: To be considered driver of record for an event, competitor must qualify kart (if applicable) and/or complete at least one (1) lap of an event. Driver substitutions must be voted on, by class, at Drivers meeting before race.
7. PRACTICE POLICY: If an entrant participates in a practice session other than the class registered, it may result in entrant being started at rear of grid for subsequent events.
8. IDENTITY OF ENTRY: The kart frame is the official entry in an event and cannot be changed without permission of the Race Director.
9. IMPOUND AREA: The top 5 karts must go to the impound area after the feature race or they will be ineligible for points and/or awards.
10. 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.
11. COMBINING CLASSES: The Race Director may combine events; classify entrants into groups according to driver experience, lap times or other factors for purposes of safety or event expediency, but not by age. Race officials may conduct events restricting certain races to certain classification of drivers or total numbers of entries.
NOTE: Any class (Except Junior Classes and Amateur) with less than three (3) entries at the first event will be abolished for the remainder of the racing season. In the event that there are two consecutive races with less than three (3) karts, the WBSW Board reserves the right to abolish the class.
12. INSPECTION: All participants will present their entries to the WBSW (tech) official for safety inspection prior to practicing, qualifying, or competing for any event. Officials and board members may not inspect any kart with which they are involved. The Tech officials (inspector) may require any competitor to submit to technical and/or safety inspection any time. Failure to do so may result in loss of all points and awards for all classes run at that event and may result in suspension of membership privileges. If an engine or part needs to be removed from a kart after it has been qualified, the driver will have a tech official check it before it is removed. The tech official will then impound the engine or part until technical inspection is complete for that class at that event.
13. 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 individuals to immediate removal from the restricted area and possible suspension of membership privileges.
14. 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. No fuels or lubricants or other hazardous substances may be disposed of in the restricted/pit area except in containers specifically designated for such purpose. Failure to comply will subject individuals to suspension of membership privileges.
15. NO DRIVING IN PITS: Karts will not be moved UNDER POWER in the restricted/pit area except for specific areas designated by the officials in charge.
16. PERSONAL VEHICLES: Vehicles for personal transportation, machine or human-powered, may be restricted from the pit area at the discretion of the officials in charge.
17. GRID AREA: Only number of individuals so designated per racing kart by officials in charge may enter the grid area. Entry to the grid area is strictly under control of the race officials and failure to comply with their directions will subject violators to immediate removal from the restricted/pit area and possible suspension of membership privileges.
18. HOT PITS: Where “hot” pit area is necessary for conduct of event, all regulations regarding grid area apply. (Example: Oil Change or refueling in infield, etc.)
19. REFUELING: Karts may NOT be refueled on the grid (past pump around). During refueling, engine must be stopped and the driver must vacate the kart.
20. QUALIFYING: All karters will be required to go through the pump around with their class and qualify with their class. Anyone who does not follow this procedure will not be allowed to qualify and must start in the rear of the feature race. A maximum of 26 karts will be qualified to start a race. Any kart that fails to make the race will be awarded points as defined in the points system. In the event of a tie in qualifying times, the driver with the 2nd fastest lap will break the tie. If the 2nd fastest laps are the same, the 3rd fastest lap will break the tie.
21. RLV mufflers are required at all races.
22. Tire warmers and rolling kart stands are not allowed past the pump around.
23. Transponders must be mounted on the inside nose of Kart.
24. Weights: 5 lbs per tab & 10 lbs per bolt on seat.
25. NO wet tires on grid.
26. DQ’d for illegal activity for performance gain Non-Drop 0.
27. DQ’d for other incidents Drop 0.

TENTATIVE RACE CLASSES

FUN CLASS
JR. SPORTSMAN I LITE
JR. SPORTSMAN I HEAVY
JR. SPORTSMAN II LITE
JR. SPORTSMAN II HEAVY
JR. SPORTSMAN III LITE
JR. SPORTSMAN III HEAVY
JR. SPORTSMAN CHAMP
JR. CHAMP
SENIOR CHAMP
STOCK MEDIUM
STOCK LITE
STOCK HEAVY
STOCK SUPER HEAVY
LIMITED MODIFIED

FLAG RULES

1. GREEN FLAG indicates track is clear for racing.
2. YELLOW FLAG indicates need for caution on entire course, to reduce speed to pace lap level with no passing permitted. Karts are to maintain single file and maintain close interval with kart directly ahead. At this point everyone having trouble will be allowed two (2) laps to get their kart lined up for the restart. Any kart that purposely wrecks another for personal gain is subject to disqualification or last place, at the discretion of the flagman, WBSW officials. If you are the cause of three (3) yellow flags you will be given the black flag, this is for all classes.
3. CAUTIONS: All persons causing the caution will be placed to the rear of the field. All karts which wreck/spin to avoid the wreck will not be penalized and will restart in the order indicated by the last scored lap. Any kart involved in a wreck caused by a lap kart will retain his position. The cause of the caution will be determined by the Flagman and Race Director.
4. RED FLAG indicates that all competitors stop IMMEDIATELY or at point designated by officials on the course.
5. BLUE FLAG indicates you are being lapped and must yield the line for lapping karts to pass.
6. BLACK FLAG indicates you must proceed immediately to pit area or area indicated by officials. Failure to heed the black flag may result in the competitor not being scored for those laps completed after the black flag is presented and being disqualified and –50 points.
NOTE: If rolled up black flag is pointed at competitor, it is a warning that they are in danger of being black-flagged for an non-course violation such as blocking, rough-driving, etc. A race cannot be ended under a black flag.
7. WHITE FLAG indicates that there is one (1) lap to go in the event. Once displayed, the next flag shown will be the checkered flag, no exceptions.
8. CHECKERED FLAG indicates the event is completed and you are to proceed to the pits or area designated by race officials. The checkered flag is the OFFICIAL finish of the race.
9. Special flag signals may apply for certain events and will be explained at the pre-race driver’s meeting.
10.RACE STARTS: Any class running Tilotson carburetors will be allowed 2 warm-up laps prior to start of race. For all classes, 2 attempts to start the race double file will be made. At the flagman’s discretion, karts may be lined up in single file in an attempt to start. Anyone intentionally jumping start or spinning out, may be placed in the rear (flagman’s option). Two (2) laps will be allowed to solve any mechanical problems, before the green flag is taken (x-cross line-up adj. for drop outs). 11.RESTARTS: After the green flag has been taken, only a wreck or red flag, will restarts be allowed. THE CLASS WILL BE ALLOWED THREE (3) LAPS FOR DRIVERS TO BE RESTARTED (includes working on kart).
12.SPIN OUTS: Any driver who spins out three (3) or more times (unassisted) during an event may be black flagged at the discretion of the race director.
13.NON-QUALIFIERS: Will be placed in the rear of the field for the start of the feature race. (Unless the class has a full kart count)
14.RACE TIME LIMIT: All races (including Jr. classes and Rookies) will have a 20 minute maximum time limit to complete 20 laps of green flag racing. If at the end of 20 minutes, the race is under green flag, it will be allowed to continue until completed. If the race is under a yellow flag and the time exceeds the time limit (20 minutes), the class will be given a green/white/checkered flag at the direction of the Race Director. Race time will pause for Red Flag situations.
15.UNABLE TO RACE: If we are unable to qualify at the first race we will draw for points. If it happens again at any other race, we will line up by points. If we have not started racing by 6pm, we will go with qualifying order and call it a day.
SUBSTITUTE DRIVERS: One substitute driver allowed during the series year; provided the board is notified prior to the race, (at the Drivers meeting) and the class approves the substitution by a majority vote prior to the race start. Substitute must be at WBSW member.
RELIEF DRIVERS: If a driver is injured during an event and the trained EMT personnel determines that the driver should not continue to race that day, the driver may have a relief driver finish the race. The relief driver must run the original kart of entry. A relief driver does not count as a substitute driver.
BODYWORK AND CHASSIS PROTEST: Contact a track official and file protest. All body work and chassis tech are pre-race protest items only.
TECH PROCEDURE: The top five finishers of each class will report directly to impound from the scales regardless of running in another class. If you are running in another class, report to impound and wait for tech official’s release. The leader will undergo a random motor tech procedure regardless of protest status. (May check carb, coil, piston pop-up, plate, fuel, oil, etc.). Any top 5 driver (position 2 – 5) may challenge the win by posting a $125 protest fee, which will result in a complete motor teardown for the winner. The motor tear down procedure will start with the first place finisher and continue until a legal motor is found. NOTE: Any position in front of you may be protested by posting the $125 protest fee. In the event the engine is deemed illegal, the protester will receive $125 back. If the engine is deemed legal, then the protestee will keep the $125. Please bring the following items with you to the tech room: 3/8”-7/16”-1/2” wrench or socket and ratchet, ¼” and 5/16” nutdriver, Allen wrenches to remove carb, header, carb from tank, air filter, motor mounts, spark plug wrench, ¼”, or 5/16” wrench or socket and ratchet to remove rod, flywheel tools, screwdriver, valve spring tool, and a box to place parts in. Animal motors may require both metric and American tools.
RED FLAG SITUATIONS: Restart and finish race.

SAFETY EQUIPMENT

1. HEAD GEAR: Full coverage (full face) helmets designed for competitive motorsports use complying at minimum with Snell Foundation 2000 specifications are mandatory. Helmet must be in good condition and will be 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.,br /> 2. EYE PROTECTION: Eye protection is mandatory, either goggles designed for motorsports use or a full visor integral with helmet.
3. NECK BRACES: Collar-type, unaltered neck braces designed for motorsports use are mandatory in all classes.
4. DRIVER APPAREL: Drivers are required to wear jackets of leather, vinyl or abrasion resistant nylon or equivalent and full-length pants to prevent or minimize abrasions. Shoes, socks and gloves are mandatory. FIRE RETARDANT SUITS ARE HIGHLY RECOMMENDED.
5. Chest protectors required for all Jr. classes except for Jr. Champ. IMPORTANT NOTE: If hair extends appreciably from beneath helmet level it is MANDATORY that participants wear “balaclava” or head-sock retaining hair from extending outside helmet. Also, no apparel items such as bandannas, sweater hoods, loose belts, etc. will be permitted.
6. SAFETY TECH: All driver personal safety equipment is subject to pre-tech inspection.

POINTS

1. RAIN OUT: If an event is rained out, it will be made up on a TBD rain date. In the event that a race is called due to bad weather, it will be announced by 4:00 pm the day before the race.
7. POINTS ELIGIBILITY: All Karts must take the green flag, go through scoring at least once and weigh in to receive points. Entrants must weigh in after each event and it is the driver’s responsibility to make certain that scale personnel checks and records weight after event. Entries must be scored in 5 of 6 events per class to be eligible for awards at the year-end banquet.

SUSPENSION

1. SUSPENSION TERMS: The board 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 Association or any other just cause, if such action is determined by the Board to be in the best interest of the Association.
2. 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.
APPEAL PERIOD: Upon notification of suspension or termination, individual shall have the opportunity to request a hearing.
APPEALS BEFORE THE MEMBERSHIP: Appeal will be heard and voted on before the next race.

GENERAL RULES FOR SPRINT OVAL CLASSES

1. Besides compliance with the spirit and intent of the rules, overall quality of workmanship will be considered in the acceptance of a kart presented for competition.
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.
3. FRAME: Of proven safe design, main frame members shall be constructed of minimum 1.0” diameter, 1.4 max, minimum tubing wall thickness at 1.0” diameter is .078”. Minimum wall thickness at 1.125” diameter or greater is .060”. Cold rolled electric weld (ERW) steel tubing or other material of at least equal strength. Main frame rail members may be no higher than a line projected horizontally between the front and rear wheel hubs.
4. WHEELBASE: Maximum 43.0”, minimum 40.0”, as measured longitudinally between the true axle centers. Wheel base will be measured on both sides.
5. MINIMUM TREAD WIDTH: 28.0” as measured from outside of one tire to inside of opposite tire laterally.
6. OVERALL MAXIMUM WIDTH: 50.0” for all classes
7. OVERALL MAXIMUM LENGTH: 74.0”
8. HEIGHT: Maximum of 26.0”
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.
10.WEIGHTS: All non-structural weights added to meet minimum kart/driver weight requirements must be bolted securely to the kart. Bolts of minimum 5/16” diameter must be utilized to secure weights, cotter-keyed or double-nutted. Mounting of weights to nerf bars is prohibited. All weights must be painted a bright color such as WHITE or YELLOW. You can only have 5 lbs per tab and 10 lbs on seat.
11.DRIVER WEIGHT AND WEIGH-IN: All drivers are subject to a minimum combined kart/driver weight prior to events and a mandatory post-race weight check. Points will be awarded to only those satisfactorily completing post-race weight check.
12.Use of suspension components of any type, including springs, shocks, etc., is prohibited.
WHEELS & TIRES
1. TIRES: Burris Pneumatic only SS 33 B or A, designed for racing application types only, maximum diameter 12.5”, minimum diameter 9.0”. Tires must be available to general market at least 60 days prior to use in any sanctioned event. All manufacturers numbers must remain legible on the tire. Silicon or tape may be used to cover numbers. Champs must run Burris SS-55 tires.
2. WHEELS: Material optional, but must be a proved design capable of maintaining tire bead seal in competition conditions. Max width outside 10 3/8”.
3. Clip-on wheel balancing weights are not to exceed one-fourth (1/4) ounce weight each. Additional security is suggested when utilizing stick-on weights. A lack of security is not grounds for disqualification.
4. WHEEL HUBS must be constructed of metallic materials.
5. WHEEL BEARINGS: Ground-ball or roller-type bearings only. Wheel bearings must be adjusted so there is no excessive wheel play.
6. 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. Castor adjustment and straight axle do not require cotter-keys.
7. The use of castle-type nuts is suggested. Bolts must be keyed in such a manner to prevent any movement of bolts or nuts without key removal.
8. REAR AXLE ASSEMBLY: Axles may be solid or tubular of one-piece design. Minimum diameter is 25 mm (25.4 millimeter =1.0”) Max. dia. 1 ¼”. Both driving wheels must be locked to the rear axle with a “live” axle design.
STEERING
1. Must be of direct, mechanical type. All steering assembly bolts and nuts, including spindle bolts, must be cotter-keyed and/or safety wired. All bolts will be minimum 14,000-il. tensile strength and be minimum ¼” diameter, and at least grade 5 or US Mark 3 rating. All rod ends must have universal type swivel joints.
2. SHAFT 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.
3. Tiller/vertical shaft steering systems are not allowed.
4. STEERING WHEELS: Steering wheels may be completely circular, minimum 10” diameter and minimum three (3) spoke design; or may be butterfly-type with 10” minimum diameter, four (4) spoke design with minimum 5” inch grip length on opposing sides per drawing.
BRAKES:
1. All karts must have brakes working in such a manner to a minimum, brake both rear wheel 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.
2. Dual braking systems will consist of two (2) individual braking systems on separate brake discs or drums.
3. Master cylinder bolts and master cylinder roll pins must be cotter pinned or safety wired.
DRIVE LINE:
1. Clutches are mandatory in all classes.
2. No wet clutches in 4-cycle.
3. All chain driven karts must be equipped with a chain guard designed to retain a broken chain.
4. 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.
5. #35 Chain only allowed in any 4-cycle class.
6. Chain oilers are prohibited.
FUEL SYSTEM:
1. Fuel tanks must be securely bolted to primary structure/frame of the kart. Fuel tank must be located within main frame rails beneath the steering shaft unless integral part of engine. Maximum of one (1) fuel tank permitted with maximum seven (7) quart capacity. Fuel line will be of adequate length to connect between fuel tank and carburetor. Excessive fuel line will not be allowed. Must be attached to primary kart.
2. Fuel tanks must be constructed of puncture-resistant materials and have a secure, leak-proof fill closure.
3. No pressurized fuel systems are allowed.
BODY COMPONENTS:
1. All bodywork will be neat in appearance and security mounted. Must be attached to primary kart.
WINGS, SPOILERS, BELLY PANS AND NOSE CONES
1. Maximum width of kart 50”, with the exception of air filters. This includes bodywork, nerf bars, carburetors, etc. Fairing may extend past front tires.
2. Flexible (rubber-type) skirting allowed in those classes with nose cones, fairing, etc. only.
3. Bodywork must accommodate applicable bumper/nerf bar requirements.
4. Karts must have completely open cockpits as view from above, containing driver’s torso, arms, legs, feet, etc.
5. Spoilers, fairing, side pod and wings will be consisted of high strength plastic or fiberglass only. Sharp corners or edges are not allowed. Materials used for side pod must be shatter proof. Any aluminum or metal used for support must be enclosed.
6. Body components may not be adjustable while kart is in motion. Extended bumpers are allowed.
7. All wings, fairings, nose cones, etc. must be securely attached to kart primary structure.
8. Steering area “bubble” fairings are allowed in any class EXCEPT Junior Sportsman I and Junior Sportsman II, providing they meet the following criteria: maximum width 14.0 inches by 14.0”. Minimum clearance between bubble fairing and any tank or bodywork, 6.0”. If an optional connector strip is added between the front nose cone and the bubble it must be attached to the nose. The maximum width of that strip is 6.0” and said strip may not cover the feet of the driver. The bubble fairing must be mounted with easily bendable tabs or struts and all edges of the bubble fairing and mounting tabs or struts must be rounded, so as not to present a hazard to the driver. Bubble fairing connector strip, if used must be a minimum of 6.0” from all other bodywork and must be a minimum of 3.0” from the steering area fairings are allowed in the Junior Sportsman I & II classes.
9. All bodywork with the exception of the bubble fairing must be a minimum of 6.0” from the steering wheel when the front wheels are in a straight-ahead position.
NOTE: This rule is to insure that there is a minimum of 6.0” between any bodywork and/or tank and the steering wheel, allowing room for driver entry/exit.
10.Full floor/belly pan is allowed providing it is within the area of the main frame rails and no higher than the center of the rear axle (all classes).
11.Vertical plane (sides) of wheels and tires may not be enclosed.
12.Front fairing (“nose cone”) must be open above driver’s legs and feet. Pedals must be visible in the neutral position when viewed from above. Junior Sportsman I and Junior Sportsman II must run the junior (low rise) front fairing.
13.NUMBERS AND NUMBER PANELS: Four (4) numbers are to be displayed on the kart, including one at the front of the vehicle as viewed from the front; on both vertical side sections, positioned in area between front and rear wheels; and a rear vertical plane visible by facing the vehicle from a rear perspective.
14.FRONT BUMPER: Bumper must be constructed of minimum ¾” diameter steel tubing. The top of the upper “hoop” of the front bumper must be a minimum of 7 –3/4” above the ground as raced. The upper hoop must be supported in at least two (2) places in the front portion of the bumper by ¾” or larger tubing, uprights. These uprights shall be within ½” of vertical when measured 3.0” down from the top of the upper hoop. Bumper must be supported by two (2) vertical supports or as supplied by manufacturer.
15.Front bumper that incorporate pedal mounting points must be either welded to the frame or throughbolted or pinned with safety wire/cotter pins.
16.REAR BUMPER: Constructed of ¾” diameter steel tubing as positioned so that:
a. Maximum height: 7 –1/2 inches (as raced)
b. Minimum height: No lower than rear axle
c. Maximum width: No wider than rear tires
d. Minimum width: No less than lateral width of main frame rails.
17.NERF BARS: Nerf bars must be constructed of minimum ¾” diameter steel tubing. 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 and the rear of the kart in a straight line to where it attaches to the kart at the front. The nerf bar may not protrude over 1 inch past the widest tire on each side. Double high nerf bars are required.
18.Sprint style “bucket” seats only, no lay down seats allowed. Seat must securely locate driver laterally and longitudinally. Seat must bolt securely to the frame and not be adjustable while the kart is underway.
19.It is mandatory for all karts to be equipped with a positive acting throttle-return spring.
20.Seat belts or other driver restraints are prohibited.
21.Rear view mirrors are prohibited.
22.Drivers may not utilize any type of radio communication devices.
23.Only these on-board computer systems and/or data acquisitions are allowed: RPM, cylinder temperature, speed, exhaust temperature, lap timing, and computer scoring systems.
RULES FOR CHAMP KARTS
1. WHEELBASE shall be minimum of 42.0” and maximum of 45.0”.
2. MAXIMUM OVERALL WIDTH shall be 52.0” measured outside tire to outside tire.
3. MINIMUM OVERALL WIDTH shall be 40.0” measured outside tire to outside tire.
4. OVERALL MAXIMUM LENGTH shall be 95.0”.
5. Main frame rails must be constructed of minimum 1-1/8” diameter, .083” wall thickness mild steel tubing.
6. FULL ROLL CAGE of four (4) point configuration is mandatory. Rollcage primary structure (four uprights joined by top horizontal, “hoop” that shall be minimum of 16.0” as measured laterally from outer dimension of left-side tube to outer diameter of right-side tube) must be constructed of 1-1/8” diameter, .083 wall thickness mild steel tubing. Rear uprights must be positioned to connect to the main frame rail structure at a point rearward of the rear axle centerline. Front uprights must be positioned no farther rearward than a vertical line intersecting the steering shaft hub. Minimum overall height of the rollcage structure is 38.0” measured vertically from the frame rail centerline to centerline of the upper most horizontal structure of the rollcage. ALL FOUR (4) ROLLCAGE UPRIGHTS WILL BE WELDED DIRECTLY TO THE MAIN FRAME RAILS.
7. ROLLCAGE NOTES: The following are guidelines for rollcage configuration based upon current accepted practice. Each manufacturer or individual competitor is responsible for the final design and construction of the rollcage structure, however, inspection will be made according to these guidelines with safety as the overriding intent of these rules. Decisions of the inspections and official(s) in charge will be final.
A. Rollcage “corners” and/or structure extremities must be of a rounded design. Square, triangulated or sharp-ended tub junctions on the upper “hoop” portion of the rollcage structure is not acceptable.
B. Rear uprights must be connected by a lateral, horizontal tube at a height suitable for anchoring, shoulder restraint hardware, or at a height no higher that the driver’s shoulders when driver is seated normally.
i. The rear horizontal bar between the uprights, that attached the seat belts must be horizontal. No bends, no curves, no angles up, down, in, out or in any other way.
ii. All slip joints must be welded. Only exception will be the two side bars.
C. It is recommended that a horizontal side-protection tube extend longitudinally from the front to rear rollcage uprights at approximately driver shoulder height (when driver normally seated) on both sides of rollcage structure.
D. It is strongly recommended that a lateral hoop structure be welded across the frame to form a protective area for the driver’s foot and leg area.
E. Head rest with padding attached to rollcage structure is recommended.
F. Rollcage padding is recommended in those area adjacent to the driver’s helmet. Padding must be readily removable to facilitate rollcage inspection.
8. Besides compliance with the spirit and intent of the rules, overall quality of workmanship will be considered in the acceptance of a kart presented for competition.
9. WHEELS: Materials optional, but must be of proved design capable of maintaining tire bead seal in competition conditions. Maximum 6” diameter. No “G-Ring” or lateral supported wheels allowed.
10.TIRES: BURRIS RACING Type SS-55 ONLY. This pertains to ALL Champ kart classes.
11.Cleaning and Prepping of tires is allowed.
12.Clip on balancing weights are not to exceed one-fourth (1/4) ounce weight each. Additional security is suggested when utilizing stick-on weights. A lack of security is not grounds for disqualification.
13.WHEEL HUBS: All wheel hubs, both front and rear, must be constructed of metallic materials.
14.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.
15.Front axle nuts must be cotter-keyed and rear must be safety wired, cotter-keyed or snap-ringed. Self-clamping wheel may utilize snap-rings instead on nuts.
16.The use of castle-nuts is suggested. Bolts must be keyed in such a manner to prevent any movement of bolt or nut without key removal.
17.REAR AXLE ASSEMBLY: Axles may be solid or tubular of one-piece design. Minimum diameter is 25mm (25.4 millimeter = 1.0”) Max 1 3/8 diameter. Both driving wheels must be locked to rear axle with a “live” axle design.
18.Steering must be of direct, mechanical type. All steering assembly bolts and nuts including spindle bolts, must be cotter-keyed and/or double nutted and safety wired. All bolts will be a minimum of 14,000 lb. Tensile strength and be minimum ¼” diameter, and at least grade 5 or US Mark 3 rating. All rod ends must have universal type swivel joints.
19.STEERING SHAFT SPECIFICATION:
SOLID: Minimum .625”diameter cold-rolled steel
20.Steering shaft must be one-piece with no extensions.
21.STEERING WHEEL: Quick release type steering wheel is MANDATORY. May be of Splined-shaft or hexagonal design.
22.Tiller/vertical shaft steering systems are not allowed.
23.All karts must have brakes working in such a manner to, at minimum, brake both rear wheels equally and adequately.
24.All brake system component 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 wires or cotter keys.
25.Dual braking systems will consist of two (2) individual braking systems on separate brake discs or drums.
26.Master cylinder bolts and master cylinder roll pins must be cotter pinned or safety wired.
27.CLUTCH: Dry-type engine clutch is mandatory.
28.CHAIN GUARDS: A chain guard designed to retain a broken chain from reaching the driver is mandatory.
29.No transmission, gearbox or other device which permits a change of gear / sprocket ratios while the vehicle is in motion is allowed. Torque converters are not allowed.
30.FUEL TANK: Fuel tank is to be located and mounted in a safe manner. On classes with separate fuel tanks, if located in tail section, bottom of tail section must have minimum ¾” diameter hole to act as drain. Maximum fuel tank capacity is seven (7) quarts. NOTE – May be mounted in floor pan in a safe manner.
31.No pressurized fuel systems are allowed.
32.Fuel lines must be safety wrapped at all connecting points.
33.A full, midget/sprint type open-wheel body is mandatory. Entire cockpit area will be opened as viewed from above. Rounded, compound curve body components consisting, at minimum of nose/cowl section and tail section are mandatory. Flat and angular body components with nonrounded edges are not acceptable. Body components must be located within area defined by vertical inner surfaces of tires, except side panels may be located upon vertical plane formed by nerf bars.
34.No wings, spoilers or air channeling devices are acceptable.
35.Fiberglass or similar material is acceptable for construction of bodywork.
36.Bodywork will be contained approximately within an area defined by lines within the inner tire surfaces and within the front and rear bumpers.
37.Body components may not be adjustable while kart is in motion.
38.All body components must be securely attached to kart frame.
39.All body components shall be painted or of a colorful gel-coat type finish. A number easily readable for scoring purposes shall be included, at minimum, on nose and both sides of tail surfaces. A number panel may be included on the rollcage structure providing it does not interfere with the normal vision field of the driver.
40.A clear windshield constructed of plexiglass-type material may be added to the cowl section to a height of approximately the driver’s eye level.
41.FRONT BUMPER: Mandatory steel tubing bumper constructed of minimum ¾” diameter material must encircle the front nose area at a maximum height of 7-3/4” above the ground plane. Double bumper is strongly recommended.
42.REAR BUMPER: Mandatory steel tubing bumper constructed of ¾” diameter material must encircle the rear tail section at a maximum height of 7-1/2” above the ground plane. Double bumper is strongly recommended. Bumper must measure no less than 10.5” minimum from the backside of hoop A to the outer edge of both top and bottom rear bar of bumper.
43.NERF BARS: Double-row nerf bars constructed of ¾” diameter steel tubing are required between the front and rear wheels as viewed from both sides of the kart. Bottom bar should be no lower than normal frame ride-height. Upper bar should be no higher than top of rear tire(s). Nerf bars must extend from an area inside a longitudinal line drawn from the outer portion of the front tire(s) as viewed from above to a point no further laterally than one (1) inch outside a line along the outer tire surface(s).
44.DRIVER RESTRAINTS: A full, designed-for-racing, SFI rated, five (5) point harness is mandatory. Metal-to-Metal type fasteners are mandatory. All harness hardware must be of aircraft quality and restraining nut(s) shall be cotter-keyed and must attach to a steel plate minimum 2” square, 3/16” thickness that is welded directly to the kart frame and/or rollcage structure.
45.ARM RESTRAINTS ARE MANDATORY.
46.The driver must be seated in a bucket-type seat providing adequate lateral support and back support to a height of approximately middle of driver shoulder blades or higher. Seat must be constructed of material resisting bending or fracture. Seat must have four (4) point, bolted mounting to kart frame structure with minimum 5/16” diameter bolts and load-spreading washers. IMPORTANT NOTE: Driver’s seat must be positioned no less than six (6) inches from the nerf bar on the left side. This requirement is for “as raced” configuration and will be a routine part of post-race technical inspection.
47.It is mandatory for all karts to be equipped with a positive acting throttle-return spring.
48.REAR VIEW MIRRORS: are prohibited in all Champ classes. Drivers who have mirrors installed will be required to either remove them or tape them over prior to competing in any event.
49.Drivers may utilize no type of radio communication devices.

ENGINE SPECIFICATIONS AND TECH PROCEDURE, ALL CLASSES

BRIGGS AND STRATTON 5HP:

NOTE: All parts must be Briggs and Stratton factory production parts unless otherwise specified in this manual.. No machining or alteration of parts is permitted unless specifically noted herein.
1. AIR FILTER: Any air cleaner permitted that is installed in a safe manner. No additional holes may be drilled or taped. Filter may not be sued as an air ram. Filter adapter may not be funneled or tapered. Adapter may have rolled edge not to exceed .250” from top. Adapter may not be run without an air filter.
2. BLOCK: Must be as-produced, with no alterations or reworking. Blocks repaired from broken rod damage, etc. are permitted providing that repair does not constitute a functional modification of original block. Block may NOT be machined on intake or exhaust ports gasket surface. No bushings of any kind allowed except for bushings approved in this Tech Manual. DU Bearings may be installed in conventional block on flywheel side. Extra oil hole, 1/8” in diameter, may be drilled on flywheel side of block at crankshaft bushing to better lubricate crankshaft. Resleeving block is permitted. Back cutting of valve spring chamber is allowed in all classes. Welding of the lifter bore is allowed for reinforcement or repair. Installation of bushing in lifter bore is allowed. Chamfer of block for lifter clearance IS ALLOWED.
3. BREATHER VALVE: Stock breather chamber, part #294178 is required. Valve must be unaltered. Tech will include complete breather valve assembly including the grommet. Two (2) breather valve chamber gaskets are allowed.
4. BOLTS: Any bolt utilized to secure sheetmetal, etc. with the exception of sheetmetal secured by head bolts, may be replaced with larger diameter bolt(s). Any other bolt EXCEPT ROD BOLTS and HEAD BOLTS may be replaced providing replacement is of the same diameter. Any stock head bolt may be utilized and eight (8) are mandatory. Head bolt with stud extending above hex-area permitted.
5. BORE/STROKE: Stock cylinder bore is 2.5625” and overbore is permitted providing it doe not exceed 2.6025” (approximately .040” overbore). No circular or machine grooving of cylinder is allowed in any position of cylinder. Angle boring is not permitted. Stock stroke is 2.4370, plus .007” of minus .010” for wear. Minimum crankshaft journal diameter is 0.990”. Stroke is checked by pushing piston down to take up play of rod clearance. Stroke is checked from bottom dead center (BDC) to top dead center (TDC).
6. CAMSHAFT: Only stock factory camshaft with alignment as shipped from factory is permitted. There is no visual tech on the camshaft lobes liter surface, however, lobes must remain flat and of original width. Maximum camshaft base circle is .770”
TABLE 1 Camshaft Profile Limits
Exhaust Intake
Lift Degrees Lift Degrees
0.050 38 BBDC to 33 BBDC 0.500 7 BTDC to 0 TDC
0.100 21 BBDC to 16 BBDC 0.100 10 ATDC to 17 ATDC
0.150 2 BBDC to 3 ABDC 0.150 29 ATDC to 36 ATDC
0.200 21 ABDC to 31 ABDC 0.200 55 ATDC to 64 ATDC
MAX LIFT .233 MAX LIFT .233
0.200 76 BTDC to 65 BTDC 0.200 43 BBDC to 33 BBDC
0.150 48 BTDC to 40 BTDC 0.150 13 BBDC to 6 BBDC
0.100 28 BTDC to 21 BTDC 0.100 6 ABDC to 13 ABDC
0.050 10 BTDC to 4 BTDC 0.050 23 ABDC to 31 ABDC
EZ-SPIN START: 45 to 60 ABDC (degrees)
EZ-SPIN LIFT BASE: .013” minimum, .019” maximum width .001” maximum travel during the 30 duration time.
EXAMPLE: If EZ-Spin starts at 0.15” it may drop to .014” and move around between .014” and .015”, but not to go above .015”. Second Example: If EZ-Spin starts at .015” and rises to .016”, it may move around between .015” and .016”, but not fall below .015”. AT NO TIME CAN THE EZ-SPIN OR THE .001” TRAVEL GO ABOVE .019” OR BELOW .013”
7. CARBURETOR:
ONLY PART #397135 CARBURETOR IS ALLOWED. Carburetor swirl insert may be left in place or removed. If installed, swirl must be in stock position and cannot be altered. Swirl is subject to removal for technical inspection. There is NO visual tech on carburetor bore finish. Maximum carburetor throat inside dimension is .695” and tech may include comparison to known stock sample. The .695” dimension includes the entire length of the carburetor bore. There may be no protrusions into the carburetor bore. Recess in carburetor from flange to throttle bore is .726” maximum and must remain as-cast. Maximum carburetor air horn (inlet area) dimension is 1.011” (checked with 1.011 NO-GO GAUGE) NO-GO area is machine area at or below breather hole. Entirety of carburetor casting will remain stock. No aftermarket coatings are permitted. Breather tube must be removed from the carburetor. Choke can be removed entirely; however, if retained, it must remain stock and complete. Choke stub subject to removal in tech. Holes left after removal of choke may be plugged so long as plugging does not protrude into air horn area. Main metering hole must be under .062”. Idle hole must be under .028”. Bore of tapered area from air horn to throat of carburetor cannot be altered. Short tube of carburetor to be removed and checked with .066” no-go. Gage may not go thru tube to screen. The screw that mates the butterfly to the throttle shaft must have a minimum length of .322. The butterfly must have a min. thickness of .059” where it mates to the throttle shaft.
a. Jets must have stock recess on back side.
b. Hole size in tech is NOT a tech item. May be drilled to any size.
c. No flat-back jets are allowed.
d. No recessing of holes permitted from back side.
e. No funneling of holes permitted.
f. No oblonging of holes permitted.
g. Diaphragm side CANNOT be used to create a pressure fuel feel.
h. No drilling of holes ANYWHERE in the carburetor.
i. No modification to throttle shaft, butterfly or any portion of the air passageway other than carburetor bore is allowed.
j. Diaphragm side of carburetor parts MUST be installed as supplied from the factory. Diaphragm cover plate MAY be surfaced to insure a proper seal. No silicon or other material may be applied to diaphragm side of gaskets. Use of aftermarket diaphragm is allowed if it is the same design and made of similar material as stock.
k. Cup and spring must be stock. Bottom of cup cannot extend above surface of carburetor.
l. No long brass pick-up tube allowed.
m. A tab to reinforce a broken tank bolt ear on the carburetor-to-tank flange of carburetor is allowed.
n. Felt washer part #270167 must be on carb shaft under lever.
o. A washer or coin may be crimped or clued on mixture needle. Area past mixture screw end is a non-tech item.
p. Rubber band or spring may be utilized to hold choke open.
q. Stop-arm on throttle shaft is NOT a tech item. Arm may be bent, filed or cut.
r. Remote mechanical carb adjusters legal in all stock classes.
Stop-arm on throttle shaft is NOT a tech item. Arm may be bent, filed, or cut. Remainder of throttle shaft must be unaltered, except for throttle shaft measurement on the back edge must be .086” minimum. Front edge must be .040” minimum, machined recess-backside minimum .030”. Surface may be machined to spec, but component must retain stock configuration. USE Micrometer as NO-GO.
8. CONNECTING ROD:
Aftermarket or stock connecting rod allowed, however if non-Briggs must meet OEM specifications! No undersizing or resizing of undersized rods allowed. Newer style Briggs & Stratton connecting rod with oil hole in back of rod instead of side is allowed. Oil hole opening, new or old style rod, will be .177” NO GO. Older style may be drilled to spec. Stock rod length is 3.1283”, plus or minus .005”, measured from bottom of wrist pin to top of crank journal. Rod cannot be lighter than known stock rod. Raptor II rod must be used as cast from the factory. NOTE: Oil dipper is a non-tech item in all classes. Except on Raptor II and Raptor III style rod where dipper is part of rod. Part #555907.
9. CYLINDER HEAD:
Stock Briggs & Stratton 5HP cylinder head, as shipped from factory, is only configuration approved. Machining of gasket surface and top of head bolt holes is permitted. No machining of any other portion of head permitted. Head bolt holes .348 maximum. Three (3) planes of head interior surface are subject to check by depth-gauge to establish their proximity to the gasket-area surface, including .011” above piston area; .408” in area approximating junction of plug hole and cylinder radius; and .300” in area above valves opposite cylinder bore area. Carbon build-p on either the head or piston that cannot be readily wiped off with a dry cloth will be considered part of the head and/or piston for tech measurement purposes.
10. CRANKSHAFT:
Stock factory crankshaft mandatory. Lightening, polishing of counterweights, addition of metal or other material is not permitted. Hardening of stock crankshaft is permitted in all classes to reduce premature journal wear. Crankshaft may be clearance to a minimum of .775” to permit easier removal of the bearing. The power-take-off journal of a sleeve-bearing crankshaft may be machined (turned-down concentrically) to permit its use in a ball bearing block. Offset crankshafts are not permitted.
NOTE: Aftermarket bearing of non self-aligning type, with or without shields, is permitted. OIL DIPPER IS A NON-TECH ITEM IN ALL CLASSES.
11. DECK/PISTON CLEARANCE:
This dimension may NOT exceed .005” above block surface. Machining of deck surface is permitted. 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. Gasket surface must remain flat. May not be cut into fins.
12. FLYWHEEL:
ONLY stock, 5HP flywheel is permitted. Any flywheel key or NO flywheel key is allowed. Painting and coating of the flywheel (other than minimal factory overspray) is not permitted. No machining of flywheel is permitted. Chipped fins because of poor casting is allowable, however, completely broken fins are NOT allowed. Wight of flywheel shall be 6lbs 4oz MINIMUM. Any screen or guard that fully covers the flywheel fins is allowed EXCEPT NO revolving screens. All screens must be bolted to blower housing. NOTE: Old-style ratchet may be used or removed. If removed, crankshaft may be cut-off to facilitate new-style nut and use of electric starter.
13. GASKETS:
HEAD GASKET must be minimum .043” thickness. New and old-style factory head gasket AND aftermarket (of same size and material) head gaskets are permitted. Aluminum and copper are not permitted. Head gasket must check .043” minimum thickness in a minimum of three (3) places, one (1) inch apart.
CRANKCASE GASKETS: Aftermarket Gaskets approved, however, must be of same size and material as stock gasket(s). Up to three (3) crankcase gaskets are allowed. One (1) Fel-Pro multi-layer gasket is allowed. Block and side cover may be pin-punched to help prevent side cover gasket failure.
BREATHER VALVE CHAMBER: Two (2) valve chamber gaskets are allowed.
IN TAKE: One (1) or two (2) gaskets allowable on carburetor/tank joint. Blue Print O-seal carb/tank and carb/intake gaskets are allowed.
NOTE: All gaskets will be teched to known stock Briggs & Stratton gaskets. No sealer or paint allowed.
14.GOVERNOR ASSEMBLY:
Governor assembly components may be removed in their entirety. Governor shaft in block and/or side cover may be broken off or may be removed and plugged.
15. HEADER/SILENCER:
Exhaust pipe/header must extend beyond gas tank but not extend past rear bumper and have no exposed sharp edges. Header/exhaust pipe MAY NOT PROTRUDE inside of exhaust port so as to alter port configuration for performance gain. Header/exhaust pipe must be of fixed configuration, may not be adjustable, “slippy-pipe” design. No extra tubes to header permitted and no extra holes or tubes through header and/or silencer are allowed. Extra HEAT SHIELD above chain guard IS ALLOWED (all classes). A header support brace is recommended. Muffler will be teched when required, to known, stock RLV type muffler. Muffler may not be welded to pipe. No modification allowed.
16. IGNITION:
Briggs & Stratton factory stock coils are MANDATORY and must be utilized in unaltered form. NO slotting or mounting holes or machining of attaching bolts is permitted. Resistance from plug wire must be 2,000 ohms MINIMUM and 5,000 ohms MAXIMUM, as-run, regardless of temperature factor. New-style composite ignition is allowed. There must be resistance from ground to the plug wire. SPARK PLUG CONNECTOR must be stock factory type. Rubber plug boot is allowed. Coil air vane must be installed and coil must retard.
17. PISTON, PIN & RINGS:
Stock, unaltered Briggs & Stratton piston MANDATORY with minimum measurement of .937” from top of piston to wrist pin bore. Minimum piston length is 1.869”. Pin hole may not be altered or relocated. Deck above top ring may not be altered. No machining is allowed on piston. PIN must not be altered and maximum inside dimension of wrist pin is .290” and maximum outside dimension is .490”. RINGS: Three (3) rings are MANDATORY. No machining of rings is allowed. Top two 105” minimum width (for wear). Groove MUST be present on oil ring. Groove must measure .083” minimum, regardless or condition of ring. Ends of ring must remain flat. Excessive end-gapping of rings not allowed. End gap with ring compressed on ring gauge cannot exceed .500”. New-style, beveled top compression ring is approved. Raptor III piston will be allowed when available. Shrinking of ring is allowed.
Raptor III Pistion: 1.671 min. length, .937 min. length top of piston to top of wrist pin. Top 2 ring land width, .603”-.612” raptor III rings: .090 min. width top 2 rings, .058 +/- .005 thick. Oil Ring: .70” min width, .100 +/- .005 thick oil ring land width .1020”-.1032”. Raptor III wrist pin: .281” inside max .490” outside dia. Max.
18. PORTS:
Ports are non-visual tech item. Intake port is subject to .880” NO-GO gauge check. Exhaust port is subject to 1.005” NO-GO gauge check. NO ADDITON OF MATERIAL ALLOWED. Block MAY NOT be machined on intake or exhaust port surfaces. NO GRINDING is allowed on underside of valve seat. Pin-punching of inside port only is allowed. Allen bolts may be utilized to attach the carburetor and/or exhaust pipe assembly. Studs allowed for exhaust attachment.
19. GAS TANK:
Cutting of gas tank for tire clearance IS ALLOWED providing that performance of carburetor is not altered. Tank cap MUST be in tock position. Brace on tank bracket IS permitted. Stock gas cap must be utilized. No overflow tube is allowed. Acceptable cap is stock Briggs & Stratton domed cap with single vent hole and stock gasket. Cap splash shields are not permitted. Bungee-type strap may be used in ALL CLASSES to wrap around engine and gas tank to prevent loosening of parts from vibration. Repair kit may be used, however it must have open slot on top.
20. SHROUNDS & COVERS:
Engine shrouds and covers must be intact and not modified, except fixed screen may be affixed to shroud cool air intake area. Cutting of blower housing for tire clearance is permitted.
21. STARTER:
Recoil starter may be retained as produced and intact, however, if new-style recoil is removed, starter cup must also be removed.
22. VALVES:
Stock valves ONLY. Must be one (1) angle on valve and seats, intake 30 degrees, exhaust 45 degrees. Intake valve minimum diameter is 1.115”, intake seat inside diameter 1.004” (NO-GO). Exhaust valve minimum diameter is .990”, exhaust seat inside diameter, .880” (NO-GO). Valves may not be polished or lightened. Valve seat may be replaced but must stay in stock location and be Stock B&S replacement. Stock B&S valve guides allowed in intake and exhaust. Stacking of stock valve guides permitted. Any valve setting is permitted.
23. VALVE SPRINGS/LIFTERS:
Stock B&S valve springs and keepers are mandatory. Maximum intake valve spring length is 1.240”, maximum wire diameter is .087, maximum exhaust valve spring length is 1.500”, min 1.300”. Spring diameter inside .625 intake or exhaust valve. Springs must remain unaltered as supplied by factory. Springs may be sanded on the end to meet maximum length specification. Valve spring wire diameter must measure .088” minimum at three different places on the spring. Exhaust spring may be used on intake side. If intake spring is used it must remain stock. No after market springs. RETAINERS: One (1) Briggs and Stratton part #23184 Upper Retainer may be used on each valve spring. Retainers must be unaltered factory stock. Maximum lip thickness Briggs part #23184is a minimum of .050” and a maximum of .058”. Briggs part #555147 is a minimum of .015” and a maximum of .025”. Stock lower retainers must be used.
LIFTERS: No extended or adjustable lifters allowed. Head of lifters must have minimum .982” diameter 1.005 max. Chamfering and bushing of lifter bore IS allowed. After market lifters may be used, maximum length 1.606. No titanium. Lifter chamfer will be teched with 3505 no-go gauge.
24. WELDING:
No welding can be done to an engine from the cooling fins upwards.
25. No aftermarket coating allowed on any B&S factory production parts. STOCK BRIGGS & STRATTON 5HP
Technical Inspection Checklist:
NOTE: This section is intended as a general guide and order for tech of the stock 5HP Briggs & Stratton engine.
1. Remove clutch, chain guard and motor mount. Dispose of fuel and oil into a proper container.
2. Remove air cleaner, inspecting inlet area for modifications to create ram effect, velocity stack, etc.
3. Remove exhaust header pipe, inspecting for protrusion into ports area and/or extra holes in pipe.
4. Remove flywheel shroud. Inspect for flywheel guard, head shroud, cylinder shroud and coil air vane.
5. Remove carburetor and tank assembly.
6. Remove carburetor from tank assembly. Inspect tank internal bowl for position. Bracing of tank and repairing of leaks permitted. Cutting of tank for tire clearance is permitted.
7. Remove and inspect gas cap.
8. Inspect carburetor as follows:
a. Inspect for one (1) or two (2) intake gaskets. No paint or sealer is allowed on gasket(s) in stock classes.
b. Inspect swirl, if installed, for proper position, then remove and inspect for alterations.
c. Tech carburetor bore for .695 inch maximum bore size. There is no visual tech on carburetor bore. Check air horn area with 1.011 inch NO-GO gauge.
d. Knock back plug out of air horn, using .696 inch NO-GO gauge with throttle full open, gauge must not touch butterfly.
e. Remove butterfly and throttle shaft. Inspect butterfly, screw, felt washer, or rubber o-ring. Inspect throttle shaft: back portion of flat on throttle shaft must be .086 inch & .040 minimum. Stop-arm on throttle shaft may be altered. Use micrometer as NO-GO.
f. Check carburetor throttle bore for any protrusions into bore area.
g. Inspect choke assembly, if installed. Choke stub may be removed for inspection. Holes left from removal of choke assembly may be plugged but plugging may not protrude into airhorn area.
h. Remove and inspect needle assembly and jet. Needle should be stock at metering end.
i. Tech idle hole: .028 inch NO-GO.
j. Tech high-speed hole: .062 inch NO-GO.
k. Inspect short pick-up tube .066 NO-GO (remove and inspect for steel winding, if necessary).
l. Remove diaphragm cover, inspect cover, diaphragm, spring and cup.
m. Inspect long pick-up tube for steel retaining clip. One-piece brass tube is not permitted.
n. Inspect carburetor body for alterations, extra holes or passages. Aftermarket device to reinforce broken ear on carburetor flange to tank mounting is permitted.
o. If restrictor plate is used .425 purple for Rookie I, .500 blue for Rookie II, .575 Gold for Jr. Restricted. No modification of any kind.
9. Remove and inspect valve cover breather (disassemble if necessary). One (1) or two (2) gaskets permitted.
10.Remove and inspect headbolts. Headbolts must be stock type but can be any combination in length.
11.Tech head gasket for .043 inch minimum thickness at three (3) points one (1) inch apart.
12.Tech three (3) areas on cylinder head for depth of mating surface (.011, .408, .300 inch minimums). No machining is permitted except for gasket-mating surface and top of head bolt holes.
13.Check cylinder deck to piston top height, maximum of .005 inch piston protrusion measured at topdead- center.
14.Tech cylinder bore: 2.6025 inch maximum.
15.Tech stroke from bottom-dead-center to top-dead-center: 2.4370 inches, plus .007” minus .010” for wear.
16.Remove intake valve, tech for 30 degree face, 1.115 inch minimum diameter. Valve may not be modified in anyway, including lightening, polishing, refacing, etc.
17.Tech intake valve spring for 1.240 inch maximum length, .087 inch wire diameter maximum. Exhaust springs may be run on intake side.
18.Tech upper valve spring retainer (if installed) for maximum lip thickness of .050”-.058” thick, .015”- .025” thin.
19.Inspect for stock Briggs & Stratton lower valve spring retainer.
20.Tech intake valve 30 degree single angle and 1.004 inch inside diameter NO-GO. Inspect port for .880” NO-GO at entrance and for addition of material. Pin-punching inside of port only is allowed. Pressure test if necessary. Carb bolt holes cannot open into port.
21.Remove exhaust valve, tech for 45 degree face, .990” min. diameter. Valve my not be modified in any way, including lightening, polishing, refacing, etc.
22.Tech exhaust valve spring for 1.500 inch max. length; 1.300 min. length; .088 min. wire diameter.
23.Tech upper valve spring retainer (if installed) for maximum lip thickness of .058 inch.
24.Inspect for stock Briggs & Stratton lower valve spring retainer.
25.Tech exhaust valve seat for 45 degree single angle, .880 inch inside diameter NO-GO. Check exhaust outlet with 1.005” NO-GO and for addition of material. Minimum thickness of valves between top (flat area) and seating surface is to be a minimum of .035” (no knife edging of valve allowed).
26.Inspect for stock valve guides. Knurling is not permitted.
27.Tech coil for proper resistance: 2,000 ohms min.; 5,000 ohms max. Remove coil and inspect for alterations. Plug boot is ALLOWED. If coil does not read legal, wait and recheck at end of tech.
28.Set up degree wheel, pointer and dial indicator in preparation for profiling camshaft. NOTE: All cam profile ratings must be taken with zero (0) valve lash. When checking cam profile, rotate engine in normal direction of rotation only. Valves should have no clearance and no spring tension when checked.
29.Remove and inspect ratchet (if utilized) and flywheel washer. Inspect flywheel for alterations: No painting, coating, broken fins, grinding, glass-beading, sand blasting, etc. permitted. Min. flywheel weight is 6 lbs. 4oz.
30.Remove side cover and inspect for no more than three (3) crankcase gaskets. Check ball bearing installation and stock factory camshaft alignment. If removable crankgear, inspect for proper installation.
31.Remove camshaft and inspect for alterations other than lifter surface. Surface must remain flat and original width.
32.Remove and inspect valve lifters for alterations other than lifter surface. No extended or adjustable lifters. Head of lifter must measure .982 inch minimum, 1.005 inch minimum. 1.606 max length aftermarket lifter may be used. NO titanium.
33.Remove and inspect rod bolts. Must be stock components.
34.Oil dipper is not a tech item, unless it is part of the rod (Raptor II & III).
35.Remove piston/rod assembly from cylinder.
36.Tech rings as follows prior to removal from piston:
a. Top ring: Compression ring installed with bevel up. No chrome ring and no expander under ring.
b. Middle ring: Oil scrapper ring installed with outside scraper groove down. No chrome ring and expander under ring.
c. Bottom ring: Oil ring must be one-piece, installed either way. Three (3) piece oil rings are not allowed. No expander allowed. Shrinking of rings is allowed.
37.Remove rings and check top two (2) for minimum width of .105 inches. Check bottom ring for minimum width of .085 inches. Groove must be present. Groove must measure at least .083 inches regardless of wear. Oil ring must have 6 oil relief slots and ends must remain flat; excessive end gap of rings not allowed; ring gap with rings on gauge. Not to exceed .500 gap. Must be able to tech oil ring.
38.Remove wrist pin, inspect for stock circlips and separate from rod.
39.Tech wrist pin for maximum inside diameter of .290 inch, maximum outside diameter of .490 inch, and inspect for alterations. Raptor III piston allowed.
40.Tech piston, minimum length 1.869 inches; minimum top of piston to top of wrist pin is .937 inch. Inspect for alterations and/or reworking. Raptor III piston: 1.671 min. length, .937 min length top of piston to top of wrist pin. Top 2 ring land width .603”-.612”. Raptor III rings: .090 min width top 2 rings, .058 +/- .005 thick. Oil Ring: .70” min width, .100 +/- .005 thick. Raptor III wrist pin: .281” inside max, .490” outside diameter max.
41.Stock rod length is 3.1233” min and 3.1333” max. Measured from bottom of wrist pin to top of crankshaft journal. Oil hole opening, Raptor III or old style rod, is .177” NO-GO. New style cast Briggs Raptor connecting rod approved. Part #555207. Oil hole and chamfer NO-GO size to be established.
42.Remove crankshaft from block and inspect for alterations, lightening, balancing, polishing, or reworking. If removable crankgear utilized, inspect for unaltered square key. Minimum crankshaft journal diameter to .990”. Crankshaft may be cleared to allow bearing to slide on and off, however, crankshaft must be .775” minimum diameter after clearancing. Hardening of crankshaft is allowed.
43.Inspect block for alterations or reworking and stock Briggs and Stratton bushing, if installed, on flywheel side. Block repaired from broken rods are permitted if not used to disguise modifications. Removal of governor assembly is permitted.
General Notes for 4-cycle engine classes
1. Pressurized fuel systems (except for approved fuel pumps, where permitted) are NOT ALLOWED.
2. Fuel requirements (all classes)
a. Methanol fuel ONLY, with NO additives or oil.
b. It is required that a pump-around system be utilized at all WBSW events. Additional checks may include fuel sampling, hydrometer, chemical or electronic evaluation of fuel.
NOTE: Pump-around recommendations: (i) proper type and size fire extinguishers available in immediate pump around area (ii) only explosion proof type motors to be utilized on pumps (iii) area around pump-around be condoned-off by proper barrier to eliminate congestion; No Smoking signs should be posted in pump-around area; absolute minimum personnel be permitted in pump-around area.
c. WBSW reserves the right to specify fuel uses for an event and/or take samples for laboratory analysis
d. Any systems introducing an oxygen-bearing additive or any other substance not specifically approved into the engine induction system is strictly prohibited.
e. Engine lubricating oil is subject to test for oxygen-bearing and/or vapor-producing substances which are strictly prohibited. WBSW reserves the right to conduct oil sampling and testing at any time and by any method. Among approved methods may be utilization of various oil “sniffers” including: Robinair model 14970, set on low-range (unit is no longer manufactured or being repaired); TIF instruments Model 5500 or Snap-On Tools model ACT 5600. Violation of any stated fuel/oil specification subjects offender to immediate suspension. Any competitor purposely spilling fuel or lubricants on the track, grid or pit area may be subject to suspension for the entire event.
3. Oil overflow recovery system is mandatory in all 4-cycle classes. Overflow tube must run from crank case breather to approved catch-can. Overflow recovery system is subject to tech inspection. Oil catch-can must be vented to atmosphere and is subject to tech inspection.
4. Crankcase breathers are NOT ALLOWED in stock 5HP classes.
5. Battery type ignition is NOT ALLOWED in any class except open.
6. Engine will be teched on the day it is raced. All portions of the engine will be subject to tech at the end of race day. In the case of broken parts, every effort will be made to tech the parts. If this is not possible, it will be the decision of the tech official to determine if the broken part(s) would have facilitated a performance gain and their decision regarding the legality of the broken part(s) is final. Cracked and/or broken parts may be replaced during the course of an event after an engine has been sealed and/or painted only with the expressed permission of the tech officials.
7. Tachometer, temperature gauges, etc. are allowed but are subject to technical inspection.
8. Extended or additional heat shield above chain guard/exhaust header area to protect driver’s arm is acceptable in all classes.
9. Air filter adaptors in the Stock classes are subject to tech inspection at any time during an event. These adaptors should be marked (painted) along with other parts of the engine so subject after qualifying and/or heat events.
10.Where possible, a Tech kit expressly designed for teching of engines to WKA specifications should be utilized. They are available from a variety of sources. Courtesy checks may be made with dial-type calipers; however, if the component being checked is questionable, additional checks should be made with micrometers or equivalent.
11.It is recommended that post-race technical inspection in all classes be limited to weight check and engine tech as outline herein.

BRIGGS AND STRATTON SUPER STOCK:

All parts must be Briggs & Stratton factory production parts unless otherwise specified. No matching or alterations are permitted unless specifically noted. Any parts that are to remain stock are subjected to be compared to known stock Briggs & Stratton part.
1. AIR FILTER: Same as stock.
2. BLOCK: Same as stock.
3. BREATHER VALVE: Same as stock.
4. BOLTS: Same as stock.
5. BORE/STROKE: Same as stock.
6. CAMSHAFT:
Cam can be of the type centered on each end. Maximum running lift .265”. No visual tech on lobes. Gear must remain as cast.
7. CARBURETOR:
Any Tillotson HL-series carburetor with butterfly throttle assembly. No material of any type may be added in the throttle bore or venturi area of the carburetor. Venturi may not be replaced. Venturi dimensions are: minimum diameter .850”; maximum diameter .900”. Gasket, gasket sealer, or silicone may be utilized to seal air filter or velocity stack to carburetor. Carburetor must be stockappearing outwardly with the double-pumper stacks of original style on top of the carburetor. Mechanical remote carburetor adjustments are allowed. Any single-piece intake manifold permitted. Auxiliary vacuum fuel pump allowed, must be pulsed from intake.
8. CONNECTING ROD:
After-market connecting rod may be used, but must meet stock specs.
9. CYLINDER HEAD: Same as Limited.
10.CRANKSHAFT: Same as stock.
11.DECK/PISTON CLEARANCE: Same as stock.
12.FLYWHEEL: Same as stock.
13.GASKETS: Same as stock.
14.GOVERNOR ASSEMBLY: Same as stock.
15.HEADER/SILENCER: Same as stock.
16.INGITION: Same as stock.
17.PISTON, PIN & RINGS: After market piston and stock rings may be used. Piston pin must be Briggs & Stratton stock.
18.PORTS: Same as stock.
19.FUEL TANK: Same as stock. 20.SHROUDS AND COVERS: Same as stock.
21.STARTER: Same as stock.
22.VALVES: Same as stock.
23.VALVE SEATS HEIGHT: Same as stock.
24.VALVE SPRINGS/LIFTERS: Optional, including retainers. Same as limited.
25.WELDING: Same as stock.
Back facing of upper portion of valve chamber to stabilize valve spring retainers and prevent spring bind is allowed.

BRIGGS AND STRATTON LIMITED MODIFIED:

All parts must be Briggs & Stratton factory production parts unless otherwise specified. No matching or alterations are permitted unless specifically noted. No aftermarket coating allowed on any Briggs & Stratton factory production parts.
1. BLOCK:
Briggs & Stratton 5HP engine, I.C. Series allowed. Ferrous sleeves only. Pin-punching of side cover allowed to prevent gasket failure. Aftermarket ball bearing installations on the flywheel side are not permitted. Minor grinding to clearance rod and lifters is permitted. Machining of deck surface is permitted. Briggs & Stratton 4HP deck surface is permitted. Briggs & Stratton 4HP block NOT permitted. Briggs & Stratton part #398765 cool-bore, dual-bearing cylinder allowed. Back facing of upper part of valve chamber to stabilize valve spring retainers and prevent spring-bind is permitted. Sleeve block is allowed.
2. BREATHER VALVE: Crankcase breather and girdle strap are allowed.
3. BOLTS:
Any replacement bolt or stud permitted providing stock diameter is retained.
4. BORE/STROKE:
Maximum bore diameter is 2.0675”. Stroke is same as stated in stock.
5. CAMSHAFT:
Two (2) piece gear camshaft allowed. Sidecover may be ground to allow clearance for adjustable camshaft bolts. No roller camshaft allowed.
6. CARBURETOR: Same as Modified Stock.
7. CONNECTING ROD: any aluminum connecting rod allowed.
8. CYLINDER HEAD:
Stock Briggs & Stratton 5HP cylinder head required. Head cannot be machined below the flat cylinder portion of the head. No machining is allowed on top of cylinder head. Machining of two (2) pockets for valve clearance or a single, continuous relief area from side-to-side across valve area is permitted. In no instance may the relief area touch either the back or side walls of the head and should be done in a manner not to affect air flow. Head may not be o-ringed. Recess at .400” (from gasket mating surface). Must be able to hank fingernail on gasket surface.
9. CRANKSHAFT:
Minor grinding is allowed to stock crankshaft to allow for cam lobe clearance only.
10.DECK/PISTON CLEARANCE: Flat-top, no dome piston.
11.GASKETS: Head gasket is not a tech item.
12.INGITION:
Briggs & Stratton stock electronic ignition only allowed. Point plunger hole must be plugged. Coil must remain stock and teched per stock class rules. Coil air vane not required. Coil must retard.
13.PISTON: Piston must be flat-top design, aluminum. No domed piston allowed. Any pin or rings allowed.
14.SHROUDS & COVERS: Cylinder and head shroud not required.
15.VALVES:
Stock, unaltered intake and exhaust valves are mandatory. NO refacing of valves is allowed. Valve seats may be refaced as long as stock port diameter and seat angle are maintained. Briggs & Stratton stellite valves are allowed. Any metallic valve guides are allowed. Back-facing of upper portion of valve chamber to stabilize valve spring retainers and prevent spring-bind is allowed.
16.VLAVE/SPRING LIFTERS: Are non tech item.
17.OTHER: Third bearing support is allowed. Any means to pass fuel or air to the engine other than normally-aspirated carburetor, as specified, is not allowed.
18.ARC Flywheel part #6608 is mandatory. Must weigh 4lb. 13oz to 4lb. 15oz

WARTBURGS SPEEDWAY KART ADMISSION:

$10.00 ADMISSION
$15.00 ENTRY FEE PER KART
5 and under free