Bombardier SeaDoo 1989 factory shop manual, Page 85Get this manual
Section 07 ELECTRIICAL Sub-Section 02 (IGNITION TIMING)
IGNITION TIMING
NIPPONDENSO ELECTRONIC IGNITION SYSTEM
This section is mainlly divised in two parts, thle first one using top dead center gauge to verify flywheel timing mark positionThe second one using stroboscopic timing light to check ignition timingFlywheel timing mark position verification is requiredto
Rotate MAG flywheel clockwise (when facing it) until piston is just before top dead center(TYPICAL)
Outer ring
1Troubleshoot missing or broken flywheel woodruff key2 Troubleshoot flywheel corresponding to different engine type3Scribe the timing mark on new service flywheel
Always verify flywheel timing mark position before checking ignition timing
Adaptor
lock nut Adaptor
Verifying Flywheel Timing Mark Position