2000 and older 600cc liquid class
 
Sled must be a 2000 or older model to compete. Engine and model must match as original. No leaf sprung or free air engines are allowed. 
 
 600cc liquid or fan cooled engine maximum size limit
 
1 No internal engine modifications allowed.
2 Stock Drive clutch for model / tuning components may be changed.
3 Stock driven clutch for model / tuning components may be changed.
4 Stock ignition for model
5 Exhaust system must remain completely stock / muffler must be stock and unmodified.
6 Studs allowed / 3/8 over lug max
7 Carbides allowed
8 Stock OEM skis for model, No aftermarket replacements allowed
9 Gearing may be changed from stock.
10 Original chaincase / chaincase location must be used.
11 Handlebars may be changed
12 Seats may be modified from original
13 Sled must have an original operational headlight / tail light.
14 Sled must have a tether installed and it must be operational
15 Stock fuel tank must be used
16 OEM skid frame for model must be used
17 OEM track or direct replacement. Lug height not to exceed 1 inch.
18 Carbs must remain original type and size.
19 EFI or carb allowed / no modifications or reprogramming.
20 Airboxes are to be used as in stock application.
21 Front end may not be widened from stock model width. Stock OEM spindle / A Arm / Trailing arm only.
22. No leaf sprung sleds may compete.