1980 Ski-Doo Shop Manual, Page 149Get this manual
SECTION 03 SUB-SECTION 03, (IGNITION TIMING)
IGNITION TIMINGONE CYLINDER (247-277 TYPES)
Two methods are detailed In this section; the first using the timing marks stamped on the engine, the second using Top Dead Center gauge
TIMING MARK PROCEDURE
1Disconnect spark plug wire and remove spark plug,
2Remove rewind starter assembly from engine then
remove the starting pulley from magneto ring3, Rotate crankshaft until breaker points, visible through magneto ring opening, are fully opened, Adjust points gap to 0,35 mm 0.05 (,0 14" ,002) using feeler gauge and screwdriver as illustrated,
Too early Turn armature plate clockwise Too late, Turn armature plate counter-clockwise
277 Engme type marks
(ci))NOTE: Breaker points gap can change upon tighteningAlways recheck after tightening,
4Disconnect junction block at engine then connect one
NOTE: Ignition timing can change upon tighteningAlways recheck after tightening,