1971-1973 Arctic Cat Snowmobiles Factory Service Manual, Page 52Get this manual
ENGINE SERVICING (TVVIN CYLINDER) F)
Connect the continuity light wires to the two (2) black wires running from the engine1314Disconnect the continuity lightIf Dial Indicator was used, remove from the engine, using the following procedure:
Loosen the thumb screw holding Dial Indicain the adaptor and remove the Dial Indica-I
Remove the adaptor from the spark plug hole
Rotate the crankshaft counterclockwise until the indicator needle passes the specific setting (.015")Slowly rotate the flywheel clockwise until the continuity light brightensAt this point, indicator needle should read specific setting (.015")NOTE: The "F" mark and the timing mark in the crankcase should now be aligned15Install the spark plugs or replace with new plugs and set the gap at .020"Connect the spark plug lead wiresInstall the axial fan drive pulley and beltInstall the auxiliary starting pulley on the flywheel