Rules

General Rules for all 74 and older classes(Lisbon Rules)

  1. No studs except in Mod classes that allow track studding.
  2. Any type or brand of replacement track may be used, may have up to ¾ inch lug height.
  3. Suspensions may be interchanged up to model year 1978.
  4. Stock drive clutch or Power Block / Comet 94c may be used.
  5. Stock secondary clutch / No jackshaft models
  6. 3 inch spreaders are allowed
  7. Skis must be of steel construction.
  8. No adjustable handlebars – all changes must have been welded
  9. Stock appearing seat
  10. Float type carburetors allowed, bore must be smaller than port.
  11. Carbides are allowed.

General rules for 85 and older classes (Northwoods 603 Rules)

Drive (Northwoods / 603 rules)

  1. Studs allowed in all 85 and older classes, they are not required, racers choice. Max stud height 3/8 above lug.
  2. Any type or brand of replacement track may be used, may have up to ¾ inch lug height.
  3. Full coverage clutch guard mandatory in Mod classes, recommended in all classes.
  4. Drive clutch must be OEM model make and year or Comet 94c / Comet 102 / Power block replacement.
  5. Driven clutch OEM for model make and year.
  6. Chassis without jackshaft may not add jackshaft
  7. Gearing and drive sprockets may be changed.
  8. Brakes may be upgraded, mounting location must remain the same.
  9. Handlebars may be modified to fit the driver to the sled.
  10. Carbides are allowed

Engine (Northwoods / 603 Rules)

  1. Engine must remain OE for model and year.
  2. Engine mounts, exhaust systems and their mounting location must remain original for model and year.
  3. Engine may be bored to clean up bore, not to exceed .060 over Std.
  4. Aftermarket pistons allowed
  5. Intake concept and number of carbs must remain OE for the engine.
  6. Any round slide or butterfly carburetor from a stock 1985 or older snowmobile is allowed unless the class prohibits.
  7. Airboxes may be removed.
  8. Engine must be naturally aspirated.
  9. Any OEM stock production ignition 1985 or older may be used. No programmable ignitions.

Suspension / steering (Northwoods / 603 Rules)

  1. Steering column must remain OEM for model year. Handlebar or mounting bracket may be changed.
  2. Handlebars may be modified or replaced with any commercially available bar or mount. Bar end hooks may be added
  3. No gas shocks on skis, oil filled shocks only.
  4. Single carbide runners allowed, ¾ inch max below ski surface.
  5. All ski hoops and tips must be padded.
  6. Ski spreaders allowed 3” max on each side.
  7. Steel ski from any 1985 or older OEM application allowed. No aluminum or plastic aftermarket allowed

Rear suspension (Northwoods / 603 Rules)

  1. Any brand OEM or Aftermarket track may be used. Track must be used as produced with no modifications. ¾ inch lug height max. Cleated tracks may be converted to rubber, rubber tracks may not be converted to cleats.
  2. Rear suspension must be stock but may be modified to accept a 121 inch track.
  3. No remote adjusters.
  4. Wheels may be added or removed.

1974 and older classes (Lisbon Rule Classes)

  1. F/C Twin to 300cc
  2. F/C Twin to 340cc
  3. F/C Twin to 440cc
  4. Sport 300
  5. Sport300 Plus
  6. HR stock Single Cylinder
  7. HD Super Stock Single Cylinder
  8. F/A stock 250
  9. F/A stock 340
  10. F/A stock 440
  11. Powder Puff / 440cc fan 74 and older
  12. 50 Plus
  13. IFS class

1985 and older classes (Northwoods 603 / Rule Classes)

  1. F/C 400 Single
  2. F/C Twin 340
  3. F/C Twin 440
  4. F/A stock 250
  5. F/A stock 340
  6. F/A stock 440
  7. Powder Puff 440cc / Fan 85 and older

Mod Classes

  1. Mod 250
  2. Mod 340
  3. Mod 500
  4. X mod Open
  5. Outlaw single

Specialty classes

  1. Elan / Spirit 335

Youth

  1. 120 stock*
  2. 120 Mod*
  3. 200 ZR / sno scoot*
  4. Youth / Jr Novice 10-13 340 fan twin 74 and older
  5. youth / Jr Novice 10-13 340 single 75 to 85
  6. Youth / Novice 14-17 340 fan 74 and older
  7. youth novice 14-17 440 fan 85 and older
  • “And Older” will mean sleds from the year noted and all sleds made prior to that date may compete in that class.
  • “75 to 85” will mean only sleds that fall between the dates given may compete.
  • Older sleds may race up but newer sleds may not race down. Example: a 1971 may race up into the 75 to 85 class. A 1978 may not race down into the 1974 and older classes.
  • Class specifications will be defined in the Breakdown given for each class.

General Rules For Turner Single Classes

  1. Must be a production line snowmobile
  2. No Studs
  3. Carbides allowed
  4. Point Ignition Only
  5. No Reed or Rotary engines allowed
  6. Chain case, gears and driven clutch must be original.
  7. 3/4 inch lug track max
  8. 3 inch ski spreaders allowed per side.
  9. Snowflaps must be no more than 1 inch from the ground
  10. Ski Tips must be padded.
  11. Engines will be fan cooled singles only.
  • “And Older” will mean sleds from the year noted and all sleds made prior to that date may compete in that class.
  • “75 to 85” will mean only sleds that fall between the dates given may compete.
  • Older sleds may race up but newer sleds may not race down. Example: a 1971 may race up into the 75 to 85 class. A 1978 may not race down into the 1974 and older classes.
  • Class specifications will be defined in the Breakdown given for each class.