Kids Pro Ice Racing

2007-2008 Season

Champ 120 Class Rules

General

1. Snowmobile must be an ISR designated 120/4 stroke model the complies with the General Rules and Regulations section.
2. Engine, tunnel, hood must be OEM for the model.
   
3. OEM for the model belly pan required.
   
4. Modifications allowed in other 120/4-stroke classes are allowed in Champ.

Engine

1. Must be OEM for the model.  Modification and/or replacement of parts is limited to items listed in this section.
2. Engine components allowed to modify or change from OEM.
   1. Cam shaft- maximum .290 inch lift.
   2. Valves and seats.
      1. Maximum intake valve diameter 25.2 mm.
      2. Maximum exhaust valve diameter 24.2 mm.
      3. Minimum valve stem diameter 5.5 mm.
   3. Valve Springs and retainers.
   4. Tappets and push rods.
   5. Governors may be removed.
3. Engine overbore may not exceed .020" (.50 mm) of standard bore size for the model.
4. Engine stroke must be stock as manufacture's filed specifications.
5. Engine components allowed to modify, but must begin with OEM for engine model.
   1. Bearings
   2. Crankshaft
   3. Connecting rod
   4. Piston and Rings
   5. Gaskets
   6. Cylinder head
   7. Cylinder
   8. Crankcase
   9. Rocker arms
   10. Intake manifold
6. Carburetor can be bored and modified, but must begin as OEM supplied for engine model.
7. A snowmobile type diaphragm fuel pump may be added.  A pulse fitting may be added to the intake tract to be used to operate the diaphragm fuel pump.
8. Any functionally silenced exhaust system may be used.
   Notice Effective 08/09 season:The following minimum standards for straight-thru silencers are required:
   1. Inner pipe must have at least 15 holes per square inch
   2. Minimum hole size 1/16 in.
   3. Minimum 3/8 in. sound absorbing material around the entire circumference of inner pipe.
   4. Inner pipe (perforated core) must contact sound absorbing material (fiber or steel wool packing).
   5. Outer pipe must be at least æ in. larger than inner pipe.
   6. Minimum silencer length 3 in.
9. Outlet pipe must point downward and cannot protrude beyond machine width.

Drive

1. Clutching is open. CVT type transmission allowed. Drive components must be commercially available.
2. A metal clutch/chain cover must be in place at all times during operation. It must cover clutches, gears, belts, chains, starter cups and any other rotation components
3. Brakes must be properly operable at all times.
4. Track drive sprockets may be modified or changed.

Ski Suspension and Steering

1. Suspension must maintain OEM concept ( i.e. trailing arm, "A" arm, etc.) Ski suspension and steering may be changed or modified. Materials and components must meet or exceed OEM strength and structural integrity. Must maintain suspension travel with driver seated. No rigid suspensions.
2. The structural integrity of the steering and suspension systems must be maintained.
3. Maximum ski stance is 34 inches (measured between ski runner cutting edges.)

Ski and Ski Runner

1. Skis may be changed to commercially available after market skis.
   1. Minimum length for Son-cross is 20 in.
   2. Minimum length for Oval and Ice Drag is 12 in.
   3. Minimum width and turn-up for Oval and Ice Drag are as shown in illustration.
   4. Ski loop must conform to General Rules and Regulations.
2. Ski runners must meet competition and safety requirements for the type of racing (I.E. Oval or Snow cross)

Track Suspension

1. Track suspension may be altered relocated or replaced. Structural integrity must be maintained.
2. Suspension must maintain a minimum of 2 inches of useable, vertical travel with the driver seated.
3. Track and track suspension must fit and be mounted within the confines of the OEM for the model tunnel.

Track Traction

1. Track must conform to Stock class rules.
2. Track may not be reversed.
3. Traction control devices must conform to rules in Stock class.

Frame and Body

1. Snowmobile length must not exceed OEM for the model length by more than 2 inches (ski loop to rear of tunnel).
2. Overall body width must be within 2 inches of OEM for the model body width.
3. Bumpers must be padded (no sharp edges exposed).
4. Snow flap must be touching ice with driver aboard.
5. On Arctic Cats, inside liner of belly pan may be removed. An opening may be cut to clear CVT clutch. Opening must be closed off with suitable material and fasteners to protect by-standers.
6. Bulkhead may be modified or replaced; it must remain within 1 inch of the length and 1 inch of the width of the OEM bulkhead.

Ignition & Electrical

1. Ignition system must be OEM for model. Flywheel can be lightened. Lighting coil may be removed.
2. Any commercially available flywheel may be used.