1985 Ski-Doo snowmobile Service Manual, Page 345Get this manual
Section 04 ELECTRICAL Sub-section 02 (IGNITION TIMING)
To adjust, remove rewind starter assembly and starter pulleyLoosen the armature plate screws, move the plate in the appropriate direction
Install dial indicator in magneto side spark plug holeBring magneto side piston to top dead centerBack-off (rotate counter-clockwise) piston to:
ENGINE TYPE 462
DIRECT TIMING B.T.D.C1.75 mm (.069") 2.50 mm (.098") 1.75 mm (.069") 1.75 mm (.069")
A017004002
BTDC Before top dead centerTighten armature plate screws CAUTION: Make sure armature plate screws are well securedReassemble starter pulley and assemblyRecheck engine timing (make sure engine is cold)Look through inspection hole and check if flywheel and magneto housing timing marks alignIf the marks do not correspond to the specifications, scribe new mark on the magneto housing