What is a CDI module?
A typical CDI module consists of a small transformer, a charging circuit, a triggering circuit and a main capacitor. First, the system voltage is raised up to 400-600 Volts by a transformer inside the CDI module. Then, the electric current flows to the charging circuit, charging a capacitor. A rectifier inside the charging circuit prevents the capacitor from discharging before the ignition point. When the triggering circuit receives triggering signal, the triggering circuit stops charging the circuit, allowing the capacitor to discharge rapidly to the low inductance ignition coil, which increases the 400-600 V capacitor discharge to up to 40 kV at the secondary winding. This 40 kV then jumps the spark plug gap. When there is no triggering signal, the charging circuit is reconnected and starts charging the capacitor again.
Our CDI modules are compatible with various versions of 50cc-150cc GY6/QMB139 4-stroke scooter engines as well as 50cc-150cc Chinese made Honda-style 4-stroke scooter engines.KYMCO owners please note most of our CDI modules are AC. KYMCO scooters require DC CDI modules. We have the correct DC CDI modules for KYMCO scooters in stock.
Please compare your CDI module with the pictures on each item page carefully prior to ordering.