1972 Ski-Doo Shop Manual, Page 136Get this manual
20210 bar, align the gudgeon pin with the connecting rodOnce aligned, complete the insertion of the gudgeon pin until the circlip notch at each end of piston orifice is visible
SINGLE CYLINDER ENGINE
10Place the appropriate piston .rings on the pistonUsing piston ring expander tool, open and position rings in proper grooves (fig2-2-31)
8Place dry, clean cloth over crankcase exposing only the pistonPress the circlips into locationOnce the circlips are locked into appropriate grooves, tum each circlip so that the circlip break is not directly on circlip notch break of piston (fig2-2-30)