OK, after 50+ years, this one I've not seen before -- any guesses?

Air-cooled Wisconsin 4-cylinder gasoline engine in the boom lift.

Was running normally when parked it couple of weeks ago but yesterday
didn't want to start--quite unusual; it's kinda' easy to flood if not
careful, but normally fires right up. Yesterday didn't want to fire.

Ended up cranking 'til started pulling battery down so put the charger
on. After a few minutes was looking around checking plug wires, etc.,
all on, none broke, etc. and pulled the coil discharge wire. It felt
warm. The coil itself was too hot to touch. Anybody have a cause or
experience such a thing before?

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