1999 Ski-Doo Factory Shop Manual Volume One, Page 246Get this manual
Section 06 ELECTRICAL Subsection 02 (IGNITION TIMING)
Connect tachometer wire to spark plug wire or aim tachometer toward spark plug wire without using any connection wire;
WARNING
Place ski tips against wall, raise rear of vehicle on stand so that track does not contact the groundDo not allow anyone in front or behind the vehicle while engine is runningKeep clear of track and do not wear loose clothing which can get caught in moving parts2Start the engine and point timing light straight in line with the fan cowl timing markBring engine to 3500 RPM for brief instant