1996 Ski-Doo Shop Manual, Volume 1, Page 94Get this manual
Se ion (EN GI E) Sub-Section 02 (377, 443 AND 503 ENGINE TYPES)
NOTEThe following procedures can be done without removing the engine from chassis
503 Only On theses 503 engines, piston pin needle bearing is mounted without cageUse piston pin puller (P 5290210 00) along with expansion sleeve and locating sleeve Place clean cloth or rubber pad (P5290234 00) over crankcase to prevent circlips from falling into crankcaseThen with pointed tool inserted in piston notch, remove circlips from piston Insert piston pin puller (PN 529 0210 00) then install expansion sleeve over puller rod
CLEANING
Discard all gasketsUse Gasket Remover (P 413 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 cleaning
Clean the piston ring grooves with groove cleaner tool, or with piece of broken ring