1974 Ski-Doo Shop Manual, Page 16Get this manual
a) Loose engine mount
a) Tighten engine mount nuts equallyb) Align pulleysc) Repair or replace pulley half
TROUBLE SHOOTING
1Uneven belt wear on one side onlyUneven wear
b) Pulley misalignmentc) Rough or scratched pulley surfaces
2Belt glazed excessively or has baked appearance