1985 Ski-Doo snowmobile Service Manual, Page 340Get this manual
Section 04 ELECTRICAL Sub-section 02 (IGNITION TIMING)
IGNITION TIMING
BREAKER POINTS IGNITION SYSTEMS
247 ENGINE TYPE
Two methods are detailed in this section; the first using the timing marks, stamped on the engine, the second using Top Dead Center gaugeRetighten retaining screws at this position
Timing marks 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 0.35-0.40 mm (0.014-0.016") using feeler gauge and screwdriver as illustratedToo early: Turn armature plate clockwise
AOO2004002
Too late: Turn armature plate counter-clockwise
NOTE: The arrow (embossed on the fan) indicates the timing finNOTE: Ignition timing can change upon tighteningAlWaYS recheck after tightening