1985 Ski-Doo snowmobile Service Manual, Page 28Get this manual
Section 02
(247 ENGINE TYPE)
Sub-section 01
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 spatula
ASSEMBLY
23,24, Pistoncirclips
At assembly, place the piston over the connecting rod with the letters "AUS" (over an arrow on the piston dome) facing in direction of the exhaust port
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
EXHAUST
DISASSEMBL Y
23,24,26, Piston, circlipsgudgeon pin
Place clean cloth over crankcase, then with pointed tool inserted in piston notch, remove circlip from pistonDrive the gudgeon pin out of piston using suitable drive punch and hammerCAUTION: When tapping out gudgeon pins, hold piston firmly in place to eliminate the possibilities of transmitting shock and pressure to the connecting rodAOO 1002001
To minimize the effect of acceleration forces on circlip, install each circlip so the circlip break is at o'clock as illustratedRemove any burrs on piston caused through circlip installation with very fine emery cloth