150cc no rev limit high performance racing CDI (capacitor discharge ignition) module The CDI is the “brain” of your scooter electronic and ignition system Description 150cc no rev limit high performance racing CDI (capacitor discharge ignition) module. The CDI is the “brain” of your scooter electronic and ignition system. Increase your acceleration and performance with a simple “plug and play” switch of your CDI!150cc GY6/QMB139 Honda style engines are commonly found on Chinese made scooters, pit bikes, all-terrain vehicles, go karts, and dirt bikes.Compatibility is based on matching wiring and connectors. Please ensure your make and model have the same rectangular 4 + 2 style connector prior to ordering.