1972 Ski-Doo Shop Manual, Page 154Get this manual
lWO CYLINDER 35Test automatic spark advance mechanism (centrifugal weight) by slightly rotating cam lobe to activate the centrifugal weightThe mechanism should operate freely without catching or binding36Position lock washer and magneto nut on crankshaftPlace crankshaft hold down support on magneto ring plate studs and temporarily secure using the three (3) starting pulley nutsUsing torque wrench, tighten the magneto nut to 50 ftlbsRemove crankshaft hold down support (fig2-3-40)