1984 Ski-Doo Shop Manual, Page 288Get this manual
Remove the timing inspection plug on magneto housingConnect timing light pick-up to magneto side spark plug lead (on manual start models use separate battery to supply timing light) WARNING: Place ski tips against wall, raise rear of vehicle on stand so that track does not contact the groundMake sure no one passes behind the vehicle while engine is runningKeep clear of track and other moving parts SECTION 04 ElECTR ICAl SUB-SECTION 02 (IGNITION TIMING)
NOTE: Turn headlamp "on" when checking timing
Start engine and point timing light straight into inspection hole
Timing too advanced, turn armature plate clock wise
To adjust remove rewind starter assembly and starter pulleyUsing mm Allen key, loosen the two armature plate retaining screws and lightly move plate in appropriate direction(Refer to the difference between timing marks to determine how much to move the armature plate)