[jrelliott]

Generators are noisy and the DC coming out of them contains spikes as the brushes move from one section of the armature to another. Try looking at this on an oscilloscope and you would be amazed at the signal. That is also one of the reasons a digital voltmeter goes all over the place when measuring voltage when the generator is working. Analog meters dampen out the highs and lows. The battery acts like a LARGE capacitor as it tries to smooth out the output of the generator and get it close to the voltage of the battery. My own theory is that you have some bad connections somewhere that is allowing the generator voltage to get above the electronic ignition module operating voltage.