1980 Ski-Doo Shop Manual, Page 71Get this manual
SECTION 03 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 spatulaWhen reassembling the cylinders to the crankcase, it is Important to have them properly aligned so that the cylinder head holes will match up with the studsA special tool (as per illustration) (or cylinder head itself) can be used to align the cylindersCross torque cylinder nuts to 22 N'm (16 ft-Ibs)AlIgnmg tools no, 420 876 575
NOTE: The letters" AUS" (over an arrow on the piston dome) must be visible after cleaning