1984 Ski-Doo Shop Manual, Page 285Get this manual
SECTION 04 ELECTRICAL SUB-SECTION 02 (IGNITION TIMING)
Stroboscopic timing light
Bring engine to 6000 R.P.Mfor brief instantCheck timing mark alignmentIf flywheel mark aligns within housing marks, timing is correctStop engine If the marks do not alignarmature plate must be adjustedArmature plate will have to be moved to advance or retard timingTo adjust remove rewind starter assembly and starter pulleyLoosen the armature plate retaining screws, move the plate in appropriate direction Refer to the following illustration
NOTE: To perform th is procedure we strongly recommend stroboscopic timing light which is able to go over 6000 R.P.Msuch asSNAP-ON MT 212 ELECTRO-SPECIALTYmodel 978
The ignition components are affected by temperature variation, therefore, timing must be checked when engine is cold, after MAXIMUM 20 seconds idling Connect timing light pick-up to the spark plug lead