1972 Ski-Doo Shop Manual, Page 50Get this manual
1-09-01 Suspension
DRiVEN PULLEY
GENERAL The driven pulley is variable pitch pulley which transmits power from the drive pulley to the dri ve axle sprocket by means of drive chain moun ted on sprocketsBelt engagement transmitting power to driven pulley causes chain entrainmentSpring pressure on the sliding pulley half main tains face contact with belt under all operating conditions