1999 Ski-Doo Factory Shop Manual Volume Three, Page 106Get this manual
Section 04 ENGINE Subsection 02 (599, 699 AND 809 ENGINE TYPES)
Also check for proper cylinder alignment
A01C02B
TYPICAL 1Circlip break
A06C1QA
CAUTION
Circlips must not move freely after installation; if so, replace themInstall cylinders and check for same height