1970-1979 Ski-Doo Snowmobiles Service Manual, Page 129Get this manual
122 formance type pulley, it is necessary to raise engine from frameSupport engine with wooden block between engine mount and frame cross supportNOTE: Roller shaft pulleys are spring loadedTo avoid pulley springing apart during removal of retaining bolt, pressure must be applied and held against sliding half of pulleyOn roller square shaft type pulleys, or clamps secured to outside rims of pulley halves can be used to hold spring tension (Figure 6)Exercise care when installing clamp(s) to avoid damaging or distorting pulley rims
CHAPTER SEVEN