Open Mod
Air cooled mod engines up to 800 cc allowed to compete.  Liquid sleds that already qualify for 500 mod may compete in this class as well. Engine and chassis do not need to match.
  1. Sleds must be deemed a Mod air cooled sled or a stock liquid 340 / 500 that qualifies for Mod competition to compete. No stock class sleds may enter.
  2. Air cooled engines originally designed as a snowmobile engine may compete, 800 CC limit, no cylinder limit.
  3. Any internal or external mods are allowed on air cooled engines.
  4. Any after market exhaust system allowed on air cooled engines.
  5. Leaf Sprung 1985 or older chassis.
  6. Chassis and Engine brand do not need to match.
  7. Track lug 1 inch max.
  8. Studding allowed, 3/8 above lug max
  9. Carbides allowed.
  10. Any carbs, any size. No EFI
  11. Any Ignition.
  12. Seat must be firmly secured to chassis.
  13. No alcohol fuel permitted.
  14. Engine must be naturally aspirated.
  15. Any drive clutch
  16. Any driven clutch
  17. Gears and drivers may be changed, chaincase may be rolled.
  18. Chassis mods allowed, anything deemed to be a safety issue will disqualify the sled.
  19. Skis may be any commercially available aftermarket aluminum, plastic or steel ski. Leaf springs must be spring steel and functional.
  20. Brakes may be upgraded and the location may be moved, shielding must be in place if the disc is moved to the driveshaft.