1970-1979 Ski-Doo Snowmobiles Service Manual, Page 65Get this manual
58 Piston-to-Cylinder Clearance (Quick Method)
CHAPTER FOUR
With the cylinder upside down on workbench install the piston (without rings) into the cylinder boreRefer to Figure 23 and insert the thickest possible feeler gauge between the piston and cylinder wall on the intake sideIf feeler gauge larger than wear limit specified in Table can be inserted between piston and cylinder bore, new piston or rebore is necessaryHoning Cylinder Bore
If cylinder is within wear tolerance, but lightly scored, hone by running fine stone cylinder hone lightly in cylinder (Figure 24)Clean cylinder thoroughly with detergent and water to remove all particlesCylinder Head