We suggest to use the O2 controller to further optimize both carburetion and performances in transistors. In latest generation motorcycles, thanks to lambda sensor, the CDI can rectify the fuel quantity to be injected in order to reach a constant carburetion even in Closed Loop area. The O2 controller permits to totally control the carburetion as to obtain the best air/fuel ratio. Malossi Lambda emulator is a device able to simulate signals from lambda sensor which original CDI is expected to receive. In this way, original lambda sensor is used to obtain best carburetion without the original CDI noticing failures or mistakes.