1972 Ski-Doo Shop Manual, Page 145Get this manual
TWO CYLINDER 2-3-7
20Heat the fan housing to 140160FRemove th,bearings from the fan housingNOTE: Two (2) shims positioned between the bearings are removed during bearing removal21Using needle pliers, remove circlip from fan housing (fig2-3-8)22Remove the woodruff key from the magneto crankshaft extensionTo do this, first press the cam towards the armature plate and hold it in positionUsing pin punch and hammer, drive the woodruff key from the crankshaftRemove cam, cam spring and washer from crankshaft23Remove armature plate from crankcase by removing two (2) Allen head screws and four (4) washers (fig2-3-9)