1985 Ski-Doo snowmobile Service Manual, Page 286Get this manual
Section 03 TRANSMISSION Sub-section 05 (PULLEY DISTANCEALIGNMENT)
PULLEY DISTANCE &ALIGNMENT
GENERAL
The pulley distance we will refer to, in this section, is the space separating the drive and driven pulley outside diameters (Z measurement) This basic distance is provided as an assembly guide and indicates the dimensions between which satisfactory belt deflection will be obtainedBoth pulley distance adjustment and pulley alignment must be carried out to ensure the highest efficiency of the transmission systemFurthermore, the high drive belt operation and minimum wear will be obtained only with proper pulley alignmentWARNING: Failure to correctly perform pulley alignment may cause the vehicle to creep forward at idleThe pulley distance refer to measurement All pulley alignment specifications refer to: x= Distance between straight edge and drive pulley inner half on driven pulley Sidey= Distance between straight edge and drive pulley inner half edge on the opposite side On all models except Elan, the distance must exceed distance to compensate for the twist due to the drive pulley torque