1986 Ski-Doo Factory Shop Manual, Page 364Get this manual
Section 04 ELECTRICAL Sub-section 02 (IGNITION TIMING)
ELECTRONIC IGNITION SYSTEMS
ALL ENGINES WITH NIPPONDENSO ELECTRONIC IGNITION SYSTEM
This section is mainly divised in two parts, the first one using top dead center gauge to check the flywheel timing markThe second one using stroboscopic timing light to verify ignition timing
NIPPONDENSO
TYPICAL
Checking flywheel timing mark
Roller lock nut
1, Disconnect spark plug wire(s) and remove spark plug(s)NOTE: On 503 engine typeremove fan coverWARNING: Ensure the engine is cold before fan cover removalAOO3004001
Loosen adaptor lock nut then holding gauge with dial face toward magneto, screw adaptor in spark plug hole
2Remove inspection plug on crankcase (except 503 engine type
- Slide gauge far enough into adaptor to obtain reading then finger tighten adaptor lock nut- Rotate flywheel clockwise until piston is center _