1974 Ski-Doo Shop Manual, Page 94Get this manual
At assembly torque retaining nut to 42-50 ft-Ib To increase sealing between left and right crankcase halves, on engine equipped with an external labyrinth seal, steel ring is available, (part no414 -2072)Prior to installation, the steel ring must be stretched openTo do this, slide the ring onto the neck of soft drink bottle (2 12" outside diameter)Install steel ring on crankshaft labyrinth as illustrated move circlip from pistonDrive the gudgeon pins in or out using suitable drive punch and hammerCaution: When tapping gudgeon pin in or out of piston, hold piston firmly in place to el iminate the possibilitites of transmitting shock and pressure to the connecting rod At assembly, place the pistons over the connecting rods with the letters" AUS", over an arrow on the piston dome, facing in direction of the exhaust port
Labyrinth steel ring
EXHAUST
Note: Once circlips are installed, turn each circlip so that the circlip break is not directly on piston notchRemove any burrs on piston caused through circlip installation with very fine emery cloth