Polaris 2001 High-Performance Snowmobile Service Manual (PN 9916690), Page 339Get this manual
ELECTRICAL Conversion ChartDegrees to Piston PositionB.T.D.CIf the ignition timing specification is listed in degrees only, convert to either inches or mm BTDC and use dial indicator to verify timing marksNOTE: Due to differing rod lengths and engine strokes, consult the engine model list for correct engine