1980 Ski-Doo Shop Manual, Page 102Get this manual
SECTION 03 SUB-SECTION 02, (ENGINES)
CLEANING
Discard all gasketsClean all metal components in non-ferrous metal cleanerPlace clean cloth over crankcase to prevent circlipsfrom falling into crankcase, then use pointed tool to remove Girclips from pistonsDrive the gudgeon pins in or out using suitable drive punch and hammerScrape off carbon formation from cylinder exhaust port, cylinder head and piston dome uSing wooden spatula
have to be screwed into crankcase so they do not protrude further than 15.6 cm (6.140")If it is not possible to obtain this lengtha washer must be added between cylinder head and cap nut
DISASSEMBLYASSEMBLY (2) Because of cap nutscylinder studs
NOTE: The letters "AUS" (over an arrow on the piston dome) must be visible after cleaning
Clean the piston ring with groove cleaner tool, or with piece of broken ringCAUTION: When tapping gudgeon pin in or out" of piston, hold piston firmly in place to eliminate the possibilities of transmitting shock and pressure to the connecting rodAll assembly, place the pistons over the connecting rods with the letters AUS (over an arrow on the piston dome) facIOg direction of the exhaust port