The rules and/or regulations set forth herein are designed to provide for the orderly  conduct of racing events and to establish minimum acceptable requirements for  such events. These rules shall govern the condition of all events, and by  participating in these events, all participants are deemed to have complied with  these rules. NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL  RESULT FROM PUBLICATIONS OF OR COMPLIANCE WITH THESE RULES  AND OR REGULATIONS. They are intended as a guide for the conduct of the  sport and are in no way a guarantee against injury or death to a participant,  spectator, or official. 

The race director shall be empowered to permit reasonable and appropriate  deviation from any of the specifications herein or impose any further restrictions  that in his/her opinion does not alter the minimum acceptable requirements. NO  EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM  SUCH ALTERATION OF SPECIFICATIONS. Any interpretation or deviation of  these rules is left to the discretion of the officials. Their decision is final. 

• The Management of Clinton County Fair and Speedway. 

Clinton County Speedway 600 Micro Sprint Rules follow the U6SA Micro Sprint Rules.  

1) Terms and conditions 

a) If a change or modification to the stock engine or its parts is not included in  these rules, then the modification is considered illegal. 

b) The word “stock” means un-modified factory original parts or components. c) No mixing engine parts from other motorcycle manufacturers. For example:  Only Yamaha parts can be used in a Yamaha engine. 

The case determines the model year and that is what determines the stock  

bore & stroke for that engine. 

2) Overall Engine 

a) No limited production race motors allowed. Must be a production motorcycle  engine, 4 cylinders 4 stroke. 

b) No titanium anywhere in or on the engine, unless it comes stock form  

manufacturer of engine on the production bike or used as bolts in aftermarket  rods. 

c) Must have engine, clutch, and transmission all in one unit. 

d) Must be Chain Drive. 

3) Bore and stroke 

a) 600cc Maximum displacement for an engine model that was new in 2006 or  newer. Older engines maximum displacement is 637cc. Engine model is  

defined as a manufacturer redesign of overall engine. See Specification list.  b) No strokers or de-stroked engines. 

4) Head and cams 

a) NO PORTING or deporting of intake or exhaust runners. 

i. Valve jobs, valve grinding, valve seating, valve seal modification and  

valve seat cutting are allowed. 

ii. Valve seat inserts may be reworked or replaced with any seat of  

original dimensions. Any dimensional thickness of the stock inserts  

may not be increased. Valve seats can be ground with multiple  

angles. Blending of the valve seat into the head is permitted but 

cannot extend more than ¼” into the aluminum head measured from  

where the seat meets the head.  

b) OEM Head only. 

c) Valves cannot be larger in diameter than factory stock valves. 

5) Bottom End 

a) No machining to remove weight from the crank (balancing of crank is ok) (no  after-market cranks) (no lightweight cranks) No polishing or coatings of any  kind. 

b) No aluminum connecting rods.  

c) No dry sump systems are allowed unless it comes from the motorcycle  

manufacturer as original equipment. 

6) Clutch/Transmission 

a) No removal of clutch. 

b) Clutch must remain operational. 

c) No modification to the stock transmission gears, no close-ratio gears or  nonstandard gear-ratios. All gears must remain in transmission, no removing  any gears. No polishing or coatings of any kind. 

7) Ignition 

a) No aftermarket ECU’s, stock appearing ECU only. ECU must be a production  ECU that was originally supplied by the same manufacturer as the engine.  

Racing ECU’s may be used, as long as they were originally supplied by the  same manufacturer as the engine. Ex: Honda motorcycle engines must run  ECU’s that were supplied by Honda on their motorcycle engines. Re-flashing of ECU and factory race ECUs are allowed. Rev limit for all 600cc (nothing  

larger than 600cc) engines is 16,100 rpms. Rev limit for all 636cc engines is  14, 800 rpms. U6SA specified Rev Limit must remain intact at all times (no  

switched or gear specific limiters). If a computer is hooked up to check the  

ECU it must be set to U6SA specified rpm’s, no tolerance. See specifications  list for RPM limits. 

b) All cars must have the PA standard connector for the track to check engine  rpm rev limit. These are available from the chassis manufactures and engine  builders, and at the track. All cars must leave intact the rpm wire coming from  the ECU. 

c) No aftermarket coils. 

d) No gear position sensor may be used. The sensor may be in place on the  engine but cannot have any wires connected to it. Gear position wire from  

ECU may not be switchable. 

e) No traction control device. 

f) No more than one ECU box present in or on car. 

g) A 50 rpm over rev tolerance for the purpose of tech inspection is acceptable.  (Note: this does not mean you can turn up the rpms in any ECU by any  


h) Switchable wires for changing ignition maps, fuel maps, or rev limits must be  contained and secured in the wiring harness. The wires must be taped up, not  visible, and unable to be switched in any way. 

8) Air Induction system 

a) No mechanically forced induction (turbo charging, supercharging). 

b) Any carburetors may be used on any engine, regardless of year of engine. i. Note: Switching to carburetors on engines that came with fuel  

injection usually increases the rev limiter due to the removal of the  

injectors as the ECU cuts fuel to limit rpm’s before it cuts the ignition.  

A reflash of the ECU will be required if using carburetors in order to  

comply with the rev limit rule 7. a)

c) If the engine did not come from the factory with fuel injection, fuel injection may  not be used. 

9) Exhaust 

a) A muffler must be used with the exhaust system that will keep noise levels  within individual track limits. 

10)Charging system 

a) No removing the charging system, it must remain in complete working order,  no factory racing charging systems. 


a) The engine must self-start at the beginning of the event. If it does not self-start,  the car may be pushed off and must start at the rear of the event as the  



a) No fuels other than alcohol, gasoline, and/or top lube. Nonflammable top lube  only, no exotic fuel additives, no oxidizers, no fuel enhancer top lube. 

b) Fuel tanks must contain a bladder. A fuel tank with a bladder is further defined  as a plastic outer shell with a rubber inner container. 

13)Minimum weight 

a) Minimum weight at all times is 800 pounds for winged classes and 775 pounds  for wingless classes, car and driver. If weight is added it must be firmly bolted  in place. 

14)Transponder Location 

a) Transponder location is 21” from center of front axle towards rear axle and 6”  from the bottom frame rail. 

2021-2023 Rules – Issue 12/1/2020