1978 Ski-Doo Shop Manual, Page 184Get this manual
SECTION 04 SUB-SECTION 02 (ENGINES)
CLEANING
Discard all gasketsClean all metal components in cleanernon-ferrous metal
Torque to 20 Nsrn (15 ft-lbslPlace clean cloth over crankcase to prevent circlip from falling into crankcaseUse pointed tool to remove circlips from pistonCAUTION: When tapping out gudgeon pins, hold piston firmly in place to eliminate the possibilities of transmitting shock and pressure to the connecting rodAt assembly, place the pistons over the connecting rods with the letters "AU S" (over an arrow on the piston dome) facing in direction of the exhaust port
NOTE: Torque each cylinder head individually
Scrape off carbon formation from cylinder exhaust port, cylinder head and piston dome using wooden spatula
NOTE: The letters "AUS" (over an arrow on the piston dorne) must be visible after cleaning
Clean the piston ring grooves with groove cleaner tools, or with piece of broken ring
DISASSEMBLYASSEMBLY
'EXHAUST
NOTE: Refer to Technical Data for component fitted tolerance and wear limit