The basic requirements for reciprocating engine ignition systems are the same, regardless of the type of engine involved or the make of the components of the ignition system. All ignition systems must deliver a high-tension spark to each cylinder of the engine in firing order at a predetermined number of degrees ahead of the top dead center position of the piston. The voltage output of the system must be such that the spark will jump the gap in the spark plug under all operating conditions.
Ignition systems can be divided into two clas- sifications: battery-ignition or magneto-ignition systems.
Ignition systems are also classified as either single- or dual-ignition systems. The single-ignition system, usually consisting of one magneto and the necessary wiring, was used on most small-volume, slow-speed engines. The single-ignition system is still in use on a few small, opposed-type light aircraft engines