Assuming you are using the same timing as gas,make sure the polarity of your mag pickup is correct.unplug the pickup from the loom and cut two short pieces of wire.insert one end in the wire loom and cross the wires before plugging them into your pickup. if you have an analog box whichever way gives you the most retarded position on your timing is the correct way.if you have a digital box the most advanced position is correct.if the polarity is backward the timing will scatter above 5500 or so and cause bearing problems.also make sure the mag pickup wires aren't running in the same loom or taped to the orange and black coil primary wires,this will induction fire the coil and also cause bearing problems.Bill