1985 Ski-Doo snowmobile Service Manual, Page 41Get this manual
Sactlon 02 ENGINE Sub-section 02 (253 ENGINE TYPE)
Spare parts pistons and cylinders are identified with green or red dot, it is important to match the piston with the cylinder of the same colorTo minimize the effect of acceleration forces on circlip, install each circlip so the circlip break is at o'clock as illustratedRemove any burrs on piston caused through circlip installation with very fine emery cloth
- Cross torque head cylinder nuts to 21 N.m (15 Ibfft)- Retorque both crankcase screws to N.m (80 Ibf.in)