The ignition system problems on the Cabracer came down to a faulty flywheel. Because of a misaligned stator plate, the flywheel gouged out the flywheel, most likely magnetizing the aluminum portions between the magnets. It was a maddening process to figure out because the system was producing spark, but only sporadic backfiring. In the process, an entire set of new components was purchased and replaced on the engine one at a time and then tested with no luck. The final component substituted was the flywheel, and it was like magic. The stator plate was drilled out to compensate for the clearance issue, a new flywheel was installed, and she runs well now.