Capacitor Discharge Ignition (CDI) systems perform the same basic function of the traditional points and condenser system but improves on most of the faults, IF proper care is taken (such as running a resistor plug or cap, and never letting the components get wet). Primary differences between the two systems is the use of either a magnetic signal pickup or an optical sensor to time the firing of the spark and a capacitor-inductor system used to raise the primary voltage much higher than is capable otherwise. The lack of mechanically opening points leaves the system free to never wear out and require almost no maintenance. The higher primary coil voltage means that the spark is much hotter and can fire a plug more fouled than an older system can. The real advantage to the system is it is easily adaptable to a computer control unit to handle things like timing advance under various conditions, resulting in optimum spark timing over the entire RPM range during various load conditions, not just one static RPM. Kits are available for Puch, Derbi, Sachs, Motobecane, Peugeot, Garelli, Minarelli and Tomos engines.

See Also:

Performance racing CDI

Puch CDI

Hobbit CDI Wiring