2005 Ski-Doo Racing Handbook, Page 365Get this manual
SECTION 082005 MX 550 AND 380 FC
A32CBHA
A02C2IA
CAUTION: Piston temperature must not exceed 46C (115F)NEVER USE DIRECT FLAME to heat the piston and never freeze the pinInappropriate heating procedure(s) may damage the pistonMount piston over connecting rod with the letters AUS (over an arrow on the piston dome) facing in the direction of exhaust port
TYPICAL SHOULDERED SLEEVE INSTALLATION