I'm no expert either. I had the same symptoms on my SN. I had resistance in my old wiring harness. That and the ballist resister was to much for the ignition. It needed 7 volts. I bought a new ballist resistor, no change. I then bought another coil for a ballist visitor but they have different resistance so I gave up and bought the PCM coil that was labeled for the Pertronix ignition.