1971-1973 Arctic Cat Snowmobiles Factory Service Manual, Page 68Get this manual
ENGINE SERVICING (WANKEL KM914B) Timing Ignition Spark Advance: Contact Breaker Gap: Pole Shoe Gap:
10 12 before dead center 0.016: 0.002 in(0.40.05 mm) 0.590 0.748 in(15 19 mm) (with 12 Volt 40 Watt systems) 0.315 0.472 in(8 12 mm) (with 12 Volt 75 Watt systems) Measuring Instruments: feeler gauge 0.016 in(0.4 mm)