1972 Ski-Doo Shop Manual, Page 166Get this manual
ENGINE TIMING
4Remove the three (3) starting pulley nuts and washers from magneto ring plateRemove pulley and "V" belt5Inspect breaker points conditionIf pitted, burnt or worn, replaceNOTE: Breaker points can be cleaned by inserting piece of paper benveen the points and moving it between the contact surfaces6Rotate crankshaft until breaker points (visible through the magneto ring plate) are in fully open positionAdjust points setting to .018 inch using feeler gauge and screwdriverRepeat for other set of points (fig2-&5)
Outer ring
- lock nut