Re: 40 BM ignition prob
First the serial number I think the engine is a 79 the starting number in 79 was 676B-301726 and in 80 started with 676B-303301 could you be missing the first and last digit? By the number it is a long shaft, hand crank engine or was built that way. Next they used 2 differant ign.systems Bendix and one of Jap manufacture, if we are getting close let me know which ign, it has and I will look for a wiring diagram.