Typically, the magneto consists of the flywheel (complete with cooling fins and magnet). Alongside the flywheel there will be a plastic encapsulated coil with 1 thick wire connection to the spark plug and 1 or 2 other thinner wires. As the flywheel spins past the coil a current is induced in the coil, which magnifies the voltage to produce a spark at the plug.
John, June 2008
