The pushrod I was speaking of would be a small plunger, probably 1/4" diameter, running directly into the crankcase from somewhere near the middle of the black box. This would be very like the plastic plunger on a breaker-point Briggs engine - you wouldn't see it unless you inspected the base of the black box fairly carefully. If it doesn't have a breaker in the box, with a plunger, where is the breaker? If you find a set of points under the flywheel, then the black box might only contain the coil. The capacitor needs to be close to the points, so I doubt it would have been in the box if the points were elsewhere.
