1984 Ski-Doo Shop Manual, Page 283Get this manual
SECTION 04 ELECTRICAL
SUB-SECTION 02 (IGNITION TIMING)
5Install and adjust T.D.Cgauge on engine as follows:Rotate magneto clockwise until piston is just before top dead center- With gauge in adaptor, adjust roller so that it is parallel with dial faceTighten roller lock nut
position
advance position
Adaptor lock nut
NOTE: Ignition timing can change upon tightening Always recheck after tightening
Edge gap verification
By following either of the two procedures herein mentioned the edge gap will automatically be adjustedHowever, if the edge gap is to be verified, proceed as follows: From timing marks, rotate magneto clockwise 114 of turn, (for 247 engine type hold advance mechanism centrifugal weight in full advance position (toward magneto rim)), then slowly turn magneto back counter-clockwise until timing light fluctuatesAt this point check the distance between generator coil end and magnet (edge gap), with cardboard strip of ppropriate width
Roller lock nut
- Loosen adaptor lock nut then holding gauge with dial face toward magneto, screw adaptor in spark plug hole- Slide gauge far enough into adaptor to obtain reading then finger tighten adaptor lock nut- Rotate magneto until piston is at Top Dead Center- Unlock outer ring of dial and turn it until "0" on dial aligns with pointerLock outer ring in position6Slacken the three (3) armature plate retaining screws and turn timing instrument ON7 Rotate magneto counter-clockwise until piston is at: DIRECT TIMING 3.98 0.25 mm BTDC (0.157 .010") BTDC: Before top dead centerSlowly rotate armature plate until timing light fluctuatesRetighten retaining screwsNOTE: For 247 engine type, hold advance mechanism centrifugal lever in full advance position (toward magneto rim)