 This DC current flowed through a wire to an ignition coil mounted outside of the engine.The points sometimes were under the flywheel for two-stroke engines, and commonly on the camshaft for four-stroke engines.This system worked like all Kettering (points/coil) ignition systems... the opening points trigger the collapse of the magnetic field in the ignition coil, producing a high voltage pulse which flows through the spark plug wire to the spark plug.