1. Age-Drivers age 18 and older with a valid driver’s license may compete. Drivers under 18 years of age must have a minor consent form signed by parent or legal guardian and the approval of the BHMST.


2. Roll Cage- Roll cages shall be at least 1 1/8-inch in diameter with .062-inch wall thickness. Roll cage will be made of chrome moly steel or equivalent material. The front section of the cage shall be no further back than the front edge of the steering wheel. Roll cage shall have sufficient fore and aft bracing and strength to support the weight of the car and driver in case of an upset. It is recommended that the cage have gussets at the intersecting bars to the uprights. Bends must have at least 3-inch radius. No square or pointed corners allowed. No square tubing cages allowed. Roll cage must be a minimum of three (3) inches above the driver’s helmet. It is mandatory to install a cross brace behind the seat to support the shoulder harness. You must incorporate a side bar of at least one (1) inch diameter to protect driver’s right arm. A left arm bar is also strongly suggested.



3. Bumpers and Nerfs- Cars must have a bumper extending beyond the front and rear tires. Nothing may extend beyond a tangent line from the outside edge of the tires to the bumpers. Nothing may extend beyond the outside edge of the tires or wheels, whichever is the widest. No sharp corners or design as to hook or damage. All cars must be equipped with nerf bars. Nerf bars must extend to the inside edge of the tires, but not beyond the outside of the tire.



4. Safety- Seat belts must be securely attached, and properly mounted to the car, and be used at all times. Metal to metal latches only. Five point seat belts, shoulder harnesses, and sub belt are required. Belt dates must not be over three (3) years old and must be in good condition. Arm restraints are highly recommended and used to keep the driver’s hands below the top of the roll cage. A neck brace, banner net or helmet restraint is mandatory. Helmets must be full coverage, competition type, and one the three latest approvals. No motocross type helmets allowed. All drivers will wear a flame retardant suit. Flame retardant racing gloves required. BHMST strongly suggests the use of fireproof underwear, socks, and shoes.



5. Electrics and Electronics- On and off switches must be mounted on dash with a fluorescent orange or red ring painted around it. Kill switch must be connected and functional. Electric fuel pumps must be wired to the on and off switch. No radio communication is allowed between the driver and the pits. All coils and ignition boxes must be mounted in an easily accessible location.   


6. Battery- All wet cell batteries that are mounted in or near the cockpit must be covered and properly vented.



7. Fuel- 600cc powered cars may run only BHMST approved fuels.  


8. Weight- Single Cylinder 600cc powered cars and1998 and older engines minimum car and driver weight 750 pounds. 1999-2003 engines minimum car and driver weight 785 pounds.



9. Brakes- Brakes will be of sufficient strength so as to slide the wheels while the car is in motion.



10. Shocks- Any shock absorber legal, no adjustment of shocks from the cockpit or while the car is in motion.



11. Suspension- Tread- maximum 48 inches, minimum 32 inches as measured center to center of the tires. Maximum wheelbase shall be 70 inches, minimum wheelbase shall be 50 inches, as measured from the center of the front axle to the center of the rear axle. Steering- front wheels must be connected by a solid or tubular tie rod. Rear wheel drive only. All suspension bolts except wheel nuts must be secured by some type of locking device. Splined or keyed axles are allowed.



12. Tires and Wheels- Any wheel size and tire combination may be used, but tires may not exceed 23-inches in height. Wheels must be held on with four (4) or more studs or knock off hubs. Siping, grooving, and cutting of tires is allowed. No softening or chemically treating tires allowed. 1998 and older engines are required to run a D25 Hoosier Right rear tire. 1999 – 2003 engines can run a NMMA or ASCS-2  Right Rear tire. The other three tires are open choice. 


13. Bodies- All cars must have complete bodies. Tail sections must be in place for all races. Recommended firewall between driver and engine, made of 24 gauge steel or .062-inch thick aluminum. Body must be made of aluminum, metal, fiberglass, or high impact plastic. All cars must be painted an attractive color(s). No mirrors of any kind allowed. The only part of the car allowed to be dismantled for the driver to enter or exit is a quick release steering wheel hub. Mud guards must be made of aluminum or fiberglass and allow access and vision for the driver.  All mechanically operated devices (i.e. shifter) must be mounted below the driver’s shoulders. NO IN-COCKPIT ADJUSTMENT DEVICES WILL BE ALLOWED. All fuel tanks must be properly attached and equipped with a one-way check valve to prevent spillage of fuel in the case of a rollover. 


14. Transmissions- Four cylinder engines must have transmissions with all stock working gears in working order. Any car with a shifting mechanism must have this device mounted in the cockpit area. Shift levers may be mounted on opposite side from chain drive. Chain guards are mandatory and will be made of .090-inch thick aluminum or equivalent and will run on top of chain from the front of the front sprocket to the center of the rear axle. Driver must not be able to touch the chain or sprocket while sitting in the cockpit.



15. Wings- All cars- Twelve (12) foot square maximum wing with right side board maximum 48-inches by 24- inches. Left side board maximum 48-inches by 20-inches. Left side board measurements may vary but must not exceed square inch maximum. All wings must have 1/16-inch radius edges or edging. No raw edges. No wood except for ribs or spars inside the center section. Wings cannot be lower than 4-inches below top of roll cage. Nose wings cannot exceed 24-inches in width, 18-inches in length and the side boards cannot exceed 8-inches wide by 20-inches long. Nose wings must carry car number. Top wings are mandatory to start a race. No cockpit adjustable wings of any kind allowed. No split or multi-staged nose or top wings allowed. Wing center section must be one piece.



16. Numbers- All cars must have legible numbers painted in CONTRASTING COLORS on both sides of the car and top wing. Cars must have an 8-inch number on the nose or nose wing.  All cars must have a number on the right side of the left wing side board. This number will extend from the top of the side board to the surface of the wing center section. Numbers must be separated from advertising so that they will be readable. 


17. Ballast- Any material used for ballast must be firmly attached as a part of the car’s structure. No liquid or loose ballast allowed. All weights must be painted white and have the car number painted on it.




A. 4 cycle air cooled, single cylinder engines, not exceeding 600cc are allowed:

.080 overbore, any modification will be allowed.


B. 4 cycle multi cylinder engines 600cc, 1998 and older will be:

Stock engines as run on the motorcycle, including;

Modified stock OEM carburetors that match the engine year and model. Metering rods, jets, and springs may be changed to tune the fuel curve. Any air intake box and air filter may be used. Any exhaust may be used.

Stock Heads with any valve with correct OEM specifications, with stock springs and spring retainers. Cams and cam gears will remain stock.

Porting or polishing of the head is allowed.

Head may be milled for clean up. No milling of engine block is allowed and stock OEM deck clearance must be maintained.

Stock internal charging systems will be operational. Timing advancers are allowed. No lightened rotating parts, no blueprinting or balancing or after market components allowed.

Stock pistons and stock stroke with .50 mm - .020 over bore allowed.

No fuel injection of any kind will be allowed.

Fuel will be BHMST approved gasoline only.

Stock CDI’s, HRC, and after market CDI’s are allowed.

1998 and older engine, model cars will be allowed to run 750# and a D25 right rear tire. Left rear tire will be open.


C. 4 cycle multi cylinder engines 600cc, 1999 through 2003

Stock engines as run on the motorcycle, including;

Carburetors will be stock OEM that matches the engine year and model, or most recent OEM Year and model carburetors. Metering rods, jets, and springs may be changed to tune the fuel curve. Any air intake box and air filter may be used. Any exhaust may be used.

Stock Heads with stock valves, with stock springs

and spring retainers. Cams and cam gears will remain stock with no redrilled,

slotted or altered gears allowed. No porting or polishing of the head is allowed.

No milling of the cylinder head or engine block is allowed and stock OEM deck

clearance must be maintained.

Stock internal charging systems, must be operational, with no timing advancers.

No lightened rotating parts, no blue printing, balancing or after market components.

Stock pistons, stock crankshaft with stock bore and stroke. No fuel injection of any kind will be allowed. Fuel will be BHMST approved gasoline only.

Stock CDI’s only. No after market or altered CDI’s allowed

Cars with the newer motors will weigh 785 pounds and run a NMMA, ASCS-2 or D-35 Right Rear tire. The Left Rear tire will be open. Any added weight must be securely bolted in, frame rail to frame rail and between axles.

Any sprocket (520 or 530) will be allowed. Engines and components will be randomly checked at the track.



19. Rules infractions- If any competitor is found to have illegal parts or non functional components at any time, they will lose all money won that night and all track points previously accumulated. BHMST is very serious about keeping the field even and will do everything possible to keep it that way. Any car and/or engine deemed potentially illegal by the BHMST Tech Director can be impounded and checked for compliance with the rules. The Tech Director will inspect any questionable car or component as soon as reasonably possible and release the car or component to the owner. The owner is responsible for any reassembly, costs or inconvenience associated with the inspection.



20. 2 cycle engines up to 600cc out of bike single or dual cylinder are allowed.



21. Out of town cars up to 750cc stock, must run and bring a copy of their rules.



22. All 2 cycle engines and out of town cars will be evaluated by BHMST Tech Director. After one race the car and rules will be reviewed and evaluated to make sure competitive balance is kept within the BHMST.