I had a problem like yours when I first put my Pertronix in. What I learned was that you have to retime the engine. Its not just a drop in and go. I also learned that I could not seat the part that goes down over the shaft. I had to raise it just a bit to get the hall effect and reluctor ligned up. Build yourself a little test light or buy one. Put one end to ground, the other to the distributor side of the coil and hand crank the engine. Make sure the light goes on and off six times per distributor revolution. At first (until I raised the reluctor a little) I only got two flashes.

The Sleepy Dragon