2004 Skidoo ZX Series Service Manual, Page 114Get this manual
Section 04 ENGINES (2-STROKE) Subsection 01 (377 AND 552 ENGINE TYPES)
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