1985 Ski-Doo snowmobile Service Manual, Page 197Get this manual
Section 02 Sub-section 09
(537 ENGINE TYPE)
Installation on spare crankcase without mark (ridge)REOUIRED TOOLS
From top edge of magneto side inlet port, mark crankcase at 52
Anglp finder 1414 3!:J29 001
AD' 3001022
TDC gauge 1414 1047 001
AOOQOQ1086
To correctly install the rotary valve disc proceed as follows:
Turning crankshaft counterclockwise, idrive pulley SIde) bring magneto side piston to top dead center using .DC gauge
- Position the rotary valve disc on gear to have edges as close as possible to the marks