1981 Ski-Doo Shop Manual Supplement, Page 51Get this manual
SECTION 03 SUB-SECTION 03 (I GNITION TIMING)
C.DIGNITION(NIPPONDENSO)
NOTE: Timing can be checked using stroboscopic timing light (Electro Specialty 978, Snap-on MT 215 or equivalent)The ignition components are affected by temperature variation, therefore, timing must be checked when engine is cold 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) WAR NINGPlace 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 runnin gKeep clear of track and other moving partsNOTE: Turn headlamp "on" when checking tim ing
354-454-464 Engine types
TIMING PROCEDURE
Timing mark verification
To check if timing marks on the flywheel are correct, use dial gauge (top dead center gauge PIN 414 1047 00) as per the following method Remove spark plugsRemove inspection plug on magneto housing