The technology transformation from carburetor technology to electronic fuel injection (EFI) is an effective way to meet the increasingly stringent emissions regulations.On a certain type single cylinder carbureted motorcycle engine, the intake system, ignition system and fuel injection systems were improved, and the electronic control of engine operation was achieved through a self-designed motorcycle engine electronic control system.The control system selects MC9S12XS128 microcontroller as a master chip, and the acquisition and processing of sensor signals were realized through modularized software control program.The ignition and fuel injection actuators were precisely controlled.The ignition timing and air-fuel ratio were calibrated and optimized by the use of electronic control system.The experimental results show that using the electronic control system, the engine power and economy are improved significantly.