1997 Ski-Doo Factory Shop Manual Volume One, Page 70Get this manual
Sub-Section 03
Section 03 ENGINE (377, 443 AND 503 ENGINE TYPES)
' done without removing the engine from pistonhave with the pullerto give access to MAGpin to be removed chassisCLEANING
Discard all gasketsUse Gasket Remover (P413 7085 00) to clean mating surfacesClean all metal components in non-ferrous metal cleanerScrape off carbon formation from cylinder exhaust port, cylinder head and piston dome using wooden spatulaNOTEThe letters "AUS" and arrow on the piston dome must be visible after cleaningClean the piston ring grooves with groove cleaner tool, or with piece of broken ring
NOTEThe following procedures can be
NOTEThe PTO cylinder or fan housing
503 Engine On these 503 engines, piston pin needle bearing is mounted without cageUse piston pin puller (P529 0210 00) along with expansion sleeve and locating sleeve Place clean cloth or rubber pad (P529 0234 00) over crankcase to prevent circlips from falling into crankcaseThen with pointed tool inserted in piston notch, remove piston circlip on side where piston pin puller will be inserted Insert piston pin puller (P529 0210 00) then install expansion sleeve over puller rod