Midwest Vintage Racing
Mid-mount Motor
This will be an HD and HR combined class. Motor must remain in stock location and for a chassis to qualify the motor cannot be in the bulkhead or in a forward position of the sled. (ex. the position of a yamaha motor fits this class.
1973 and older, production line model with a single cylinder fan cooled motor.
No changes or Modification allowed unless specified by these rules. If these rules do not specifically allow a change or modification, it is assumed that the change or modification is not allowed.
Engines:
- Engines must have been offered in the Brand of sled you are running!
- Engines must remain stock, no grinding, porting, sandblasting, shaving on anything.
- Pistons can be stock or aftermarket replacement, no cutting skirts. ( Max over bore .150)
-Carb can either be HD or HR (no aftermarket or billet carbs)
- Primary Clutch stock 1976 and older standard production. (must be brand specific) or 94 c dusters or Power Block allowed. No comet 100 or 102c
- Engine must have OEM point ignition (no cdi)
- Must have recoil.
- No fuel pumps allowed unless it was factory with the sled.
- None Ethanol gasoline and race gasoline only, NO E-85, Alcohol, Nitro Methane or any other fuel allowed.
- Exhaust and muffler must be stock or stock replacement. Head pipe may not exceed 2”OD. No tuners!
- If the head pipe exceeds 2” the exhaust must be stock to year, make and model of sled and may not be altered.
Fuel Tank
- Fuel tanks must mounted in stock location and must not exceed 6.5 gal. Aftermarket and homemade tanks allowed.
Chassis:
- 1973 and older, no limited production or race chassis. NO jackshaft chassis. Chassis 1976 and older may be used
as long and it is the same material and dimensions as a 73 sled. Example: 1974 Arctic Lynx II is the same Chassis
as a 1972 Cheetah.
- Bulkhead must be stock and unaltered. Reinforcement and bracing only (May be modified for 76 and older chain case only)
- 1976 and older chain cases and secondary clutch allowed. (must be brand specific)
- Skis must be original or stock replacement. NO Aluminum or unsafe skis! Any carbide allowed.
- You must run a hood and STOCK belly pan.
- 24” Leaf Spring minimum length.
- Ski spreaders allowed max 2.5” measured from center of spindle to center of ski.
- Any spindle allowed but must fit in stock unaltered bulk head.
- Numbers must be 8” and visible on both sides (Should be black and white)
- Any seat may be used and any handle bars.
- Your brakes must be in working condition (Will be checked)
- Brake may be moved from stock location and relocated (IE Extended Drive Shaft with disc) May use hydraulic brake setup off of newer sled.
- Snow flap must touch ice/snow with rider on machine.
- Must have a working tether cord and USE it. Must be mounted to the frame.
Suspension and track:
- Suspension may be 1976 and older stock production and can be reinforced only. No snow pro suspensions or “Z”. Any 1976 and older suspension is allowed as long its not a limited production or factory race sled suspension (ex. Yamaha suspension in a Polaris). May be modified to fit chassis only. (Do your homework)
- 8in idler wheel max size
- Any track allowed, Must be a minimum of 15”wide, and must be stock length or longer of the model sled you are running.
- Max cleat or lug height of 3/4”
- No aluminum or titanium cleats and rubber tracks my not be modified.
- Track Studs can measure a maximum of 1⁄2” max past cleat or lug. Will be checked with a “Go No Go ‘gauges.
- Any drive shaft and drivers can be used.
No changes or modification allowed unless specified by these rules. If these rules do not
specifically allow a change or modification, it is assumed that the change or modification is not allowed.