Midwest Vintage Racing

                                                           HR CLASS RULES

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 not allowed in this class Sachs SA340SS, SA340C, SA400 or Hirth 194R

- 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 must be original or other diaphragm carb with 2 1/4 inch bolt pattern (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.

- Engine must have OEM point ignition. (no cdi)

- Must have stock fan and stock recoil. (must be brand specific)

- 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 tuned pipes.

- 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 be mounted in stock location to year of sled and must not exceed 6.5 gal. Aftermarket or 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.

(Maybe 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 is allowed as long as its not a limited production or factory race suspension. (ex. Yamaha suspension in a Polaris). May be shortened 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.