I was in a cowboy bar down in Fort Worth Texas. In the restroom there was the usual graffiti on the walls plus a large number of ranch brand symbols. One item of graffiti really stood out though. "TRAILERED HARLEYS S@CK".
The ignition requirements for any 4-stroke engine are refreshingly similar no matter the displacement or number of cylinders. The capacitor doesn't even have to fit under the cap; if you can wire it up it will work. Glad you tried what you had access to!