1978 Ski-Doo Shop Manual, Page 213Get this manual
SECTION 04 SUB-SECTION 02, (ENGINES)
CLEANING
Discard all gasketsClean all metal components in non-ferrous metal cleanerScrape off carbon formation from cylinder exhaust port, cylinder head and piston dome using wooden spatulaEXHAUST
NOTE: The letters "AUS" (over an arrow on the piston dome) must be visible after cleaning
Clean the piston ring grooves with groove cleaner tool, or with piece of broken ring
Also make sure that the piston windows are aligned with the crankcase transfer passageswhen the gudgeon pin orifice is in-line with the connecting rod bore
DISASSEMBLYASSEMBLY