1978 Ski-Doo Shop Manual, Page 220Get this manual
SECTION 04 SUB-SECTION 04, (IGNITION TIMING)
IGNITION TIMING
Two methods are detailed in this section; the first using the timing marks stamped on the engine, the second using Top Dead Center gauge
ONE' CYLINDER,(247 TYPE)
TIMING MARK PROCEDURE
1Disconnect spark plug wire and remove spark plug2Remove rewind starter assembly from engine then remove the starting pulley from magneto ring3Rotate crankshaft until breaker points, visible through magneto ring opening, are fully openedAdjust points gap to 0.40 mm 0.05 mm COW" .002") using feeler gauge and screwdriver as illustrated
Too early: Turn armature plate clockwise
Too late: Turn armature plate counter-clockwise