1971-1973 Arctic Cat Snowmobiles Factory Service Manual, Page 20Get this manual
ENGINE SERVICING (SINGLE CYLINDER) plastic mallet, doing so while the crankcase bearing seats are still warm from heating10Carefully trim all exposed crankcase gasket from the top of the crankcaseBefore installing the piston and cylinder, clean and decarbonize the exhaust port, cylinder head and the top of the pistonNOTE: Piston ring grooves must be perfectly clean before any upper end components are replacedCheck the condition of the piston, rings, and the needle bearing and piston pinRings are the most likely items to wearTherefore, check each ring before installing on pistonNOTE: Worn rings can usually be detected by an increase in end gap or by discoloration of the piston skirt due to "blowbv", Check the cylinder walls; replace cylinder if damage If small deposits of aluminum have is evidentadhered to the cylinder bore (no grooves), the cylinder may be salvaged by very light honing process