General Stock Rules

In stock and stock based classes no changes or modifications are allowed unless specifically allowed by these rules. If these rules do not specifically allow a change or modification, then it must be assumed that the change or modification is not allowed. 

  1. The engine must be OEM for that model.
  2. Engine, engine mounts and exhaust must remain in original OEM for that model locations (of the chassis).
  3. Any internal modifications are allowed to the engine.
  4. NO external modifications allowed. Engine must remain OEM for the model appearance.
  5. Engine bore size may be increased up to 0.060 inches over stock bore. Must maintain OEM stroke for that engine.
  6. After market pistons allowed.
  7. Intake concept (for the engine) must be maintained (piston, port, reed valve, etc.).
  8. Any round slide carb from a stock qualified snowmobile is allowed. Flat slide carbs are not allowed. Air intake silencers (air boxes) may be removed.
  9. Cooling system (for engine) must be maintained and fully functioning (i.e. free-air, fan, etc.).
  10. Must be naturally aspirated.
  11. Unaltered OEM exhaust system must be used for year, make, and model. (NOTE: Factory update silencer may be used on 1975 Merc S/T.)
  12. Ignition system must be OEM for engine or aftermarket ignition of the same concept.
  13. Any snowmobile brand OEM primary clutch allowed.
    a. Any button style non roller secondary clutch is allowed.
  14. Brake components may be replaced. Must be commercially available and not modified, may be relocated. Any externally visible components must be shielded.
  15. Maximum ski widening is 3 inches.
  16. Unlimited amounts of studs. Must not exceed 3/8" from the highest point on the track. Track must be 3/4" lug or less.
  17. Unlimited sharpened area on ski runner.
  18. Sled must have a stock appearing cowl with at least 4" numbers appearing on both sides.
  19. No chassis modifications.
    a. Chassis modifications include relocation of chain case, changing angles of spindles, widening the bulk head, addition of jackshaft and tunnel must be OEM for the model.
  20. Any type leaf sprung, with 2" arch and must be functional. (Should move when the leaf spring is
    stepped on by a person weighing between 200 - 250 pounds.)
  21. No alcohol fuel is allowed.
  22. Any stock suspension 1985 or older, no aftermarket suspensions. No less than 3 inch overall track length than what came with that model.
  23. Remote adjustors are not allowed. (A remote adjustor is a system which allows the manual or automatic raising or lowering of the front skid/track while sled is in motion.) A manual adjustor is allowed, such as a limiter strap, eyebolt style adjustor.

For any questions or concerns, contact Paul Ragen 315-399-3597