2001 Ski-Doo Factory Shop Manual Volume One, Page 105Get this manual
Subsection 02
Section 04 ENGINE (377, 443 AND 503 ENGINE TYPES)
NOTE: The following procedures can be done without removing the engine from chassis
CLEANING
Discard all gasketsUse Gasket Remover (PN 413 708 500) 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 spatulaNOTE: The 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
377 Engine To remove piston pin no9, use piston pin puller (PN 529 035 503)Fully screw puller handleInsert puller end into piston pinScrew (LH threads) extracting nutHold puller firmly and rotate puller handle counterclockwise to pull piston pin
DISASSEMBLY
Remove top fan cowl, intake sockets and lower fan cowlRemove cylinder headsPlace clean cloth or rubber pad (PN 529 023 400) over crankcase to prevent circlips no10 from falling into crankcaseThen with pointed tool inserted in piston notch, remove both circlips from piston no8A01B1AA