How to distinguish DC ignition from AC ignition of motorcycles? The line from the engine magneto is usually DC ignition for four wire and AC ignition for five wire. The motorcycle magneto with AC ignition has a motorcycle ignition coil (the one wrapped) inside, and the motorcycle magneto with DC ignition has no motorcycle ignition coil. The motorcycle ignitionlighter is mainly composed of power supply, ignition coil, distributor, ignition switch, motorcycle spark plug, additional resistance and its short circuit device, high and low voltage wires, etc. If it is a carburetor motorcycle, a good refitted digital igniter should be selected. This igniter is usually equipped with a program inside, which will control the ignition advance angle more precisely to ensure more full combustion.