CDIs control the Ignition on many Carburettor models of the Modern Vespa and are an important component for reliable engine running.

Some models, such as the 50 cc 2-stroke models, already have the CDI integrated in the Ignition Coil or Electronic Unit. However, the Carburettor models of the 4-stroke modern Vespa from 125 cc and the 50 cc 4-stroke 4-Valves have a separate CDI and a separate Ignition Coil. If the vehicle comes to an unexpected standstill and the ignition spark is missing, a defective CDI may be responsible and should be replaced promptly. Unless otherwise indicated, the CDIs are suitable for models with an immobilizer.