2001 Ski-Doo Factory Shop Manual Volume One, Page 110Get this manual
Section 04 ENGINE Subsection 02 (377, 443 AND 503 ENGINE TYPES)
Hold tool firmly against piston then strike on round end of toolCirclip will move from tool groove to piston groove
NOTE: The ring compressor will not fit on over size pistonsCheck flatness of intake sockets no6Refer to ENGINE DIMENSION MEASUREMENT and look for Checking Surface FlatnessAt cylinder no4 andor cylinder head no3 installation, use aligning tool or exhaust manifold itself to ensure sealing of intake manifold and exhaust before tightening cylinder head nutsENGINE TYPE 377, 443 and 503 ALIGNING TOOL PN 420 876 171