1979 Ski-Doo Supplementary Shop Manual, Page 110Get this manual
SECTION 04 SUB-SECTION 04 (I GNITI ON TIMING )
TDC GAUGE PROCEDURE
1Disconnect spark plug wires and remove spark plugs2Remove rewind starter assembly from engine then remo ve the fan protector, starting pulley and "V" belt
With gauge in adaptor, adjust roller so that it is parallel with dial faceTighten roller lock nut
Outer ring set screw
Na E: The upper breaker point set cont rols the timing of the magneto side piston and the lower breaker point set controls the PT .Oside piston
3Rotate crankshaft until breaker points, visible throug magneto ring opening, are fully openAd Just point setting to 0.40 mm 0.05 (016" .002) using feeler gauge and screwdriver, as illustrated Repeat procedure for other set of pointsAdjust both side equally
Adaptor lock nut