Control units CDI

The CDI on the motorcycle.

CDI ( Capacitor Discharging Ignition ), refers to a high voltage capacitor ignition (HKZ) and is also called thyristor ignition.

Simplified operating principle

A capacitor is charged by DC voltage and suddenly discharged by means of a thyristor via the primary side of the ignition transformer. The high voltage generated on the secondary side is used to spark the spark plug.

The black boxes take over more and more tasks of the electronic controls ( like e.g. the control of the fuel pump relay ).
Advantages of these designs is that the system is maintenance free.
On mopeds, LKR and enduros, the CDI usually has an extra excitation winding in the alternator, which supplies the energy for the ignition. It often works without battery connection. 

Possible failure effect,no ignition spark, misfiring.

Coils and pickups are OK, supply voltage is present, no cable break, wiring e.g. side stand, clutch and gear shift contacts iO, all contacts clean and tightly connected.
Then the ignition box is probably defective.
Further containment is only possible by replacing the box.

Our CDI`s are from the accessories and are based on the originals.
The ignition curves and controls are the same as the originals.

Collection of terms:

Blackbox or CDI, loose contact, solder joints in the plug area broken, ignition failure only sporadically, ignition box defective, fluctuating supply voltage, mechanical vibrations, ignition control failure, electronic ignition systems, maintenance-free, electronic control of the ignition.