General

1. The Snowmobile must have OEM (or Factory designated replacement) engine, hood, track, skis frame, cowl, gas tank, carburetion, air box, suspension and clutch supplied by the manufacturer for the particular model. Factory designated replacements allowed.
2. Engine RPM and vehicle speed may be monitored at the discretion of the Race Director.

Engine

1. Unless otherwise stipulated in this section, all governor parts must be intact, in place and functional. Any governor spring may be used.
2. No component of the engine (including head, valves, cam, and valve springs) may be altered, changed or enlarged from the engine manufacturer's original stock specification nor may any additional components be added to the engine.
3. Blueprinting of engines is not allowed. No removal of material what so ever will be allowed. This is to include polishing port matching, deburring, glass or sand blasting surfaces or material removal for the purpose of engine balancing or other reasons.
4. There will be no more than one cylinder base gasket to a cylinder. No changes in engine dimensions can be made by gasket adjustments.
5. Spark plugs do not necessarily have to be OEM stock.
6. No carburetor/air silencer changes allowed.
7. Jetting changes are allowed
8. Remote adjustable main jet system allowed.
9. The OEM exhaust system for the model must be used in its entirety. The exhaust system must by fully contained within the confines of the cowl or the chassis and exhaust emissions from the enclosed area. Muffler components and/or silencing material must be intact at all times.
10. In order to equalize performance between the manufactures' models the following changes are allowed.
    1. Ski-Doo racers are allowed to change valve springs to Honda P/N 14751-2E1-000
    2. Arctic Cat 120 racers are allowed to upgrade to the 120 SnoPro kit consisting of valve springs and cam. The kit must be used in its entirety.
11. To enhance durability, Arctic Cat races are allowed to remove the plastic governor gear.
    

Drive

1. Brake must be functional and operational at all times.
2. OEM drive clutch must be used with no modifications.
3. Stock drive clutch engagement must be maintained.
4. No belt drives allowed.
5. Chain guard must be in place.
6. OEM gear ratio must be maintained.
7. Sprocket ratio changes may be required by circuits in order to equalize performance between the various models.

Ski Suspension & Steering

1. Front suspension must be OEM stock.
2. Front suspension must remain in its stock location.
3. Ski widening devices and/or height adjustments devices are not allowed in stock classes unless furnished as OEM and properly filed.
4. Suspension travel may be limited by means of limit straps only. Minimal suspension travel must be maintained. No rigid suspensions allowed.

Skis & Ski Runners

1. Ski must be OEM for the model and year or a commercially available after market ski with a minimum overall length of 20 inches.
2. Ski suspension components must be OEM.
3. Ski Tips must have ski loops. Steel ski loops must be padded.

Track Suspension

1. The complete suspension must be used as furnished and filed by the manufacturer.
2. Commercially available marginal snow wheels may be added to the slide rails. (Rear axle idler wheels must remain OEM for the model.)
3. Suspension travel may be limited by means of limit straps only. Minimal suspension travel must be maintained. No rigid suspensions allowed.

Track & Traction

1. The track must be OEM for the model.
2. (Oval) Track studs must not extend more than 3/8 inch above the highest point of the track.
3. (Drags) Track studs must not extend more than 3/4 inch above the highest point of the track.

Frame & Body

1. OEM hoods only. OEM hood may be painted any color.
2. Windshield may be trimmed. Exposed edges of windshield must  have safety bead.
3. Front and rear bumpers must be padded.
4. All sharp edges must be padded.

Ignition & Electrical

1. An ignition tether switch must be installed and functional.
2. Headlight and tail light must be OEM stock and remain functional.