Amidst the growing concerns for the global environment and the escalating demands for low exhaust emissions and high fuel economy small motorcycles, the electronically controlled fuel injection system (hereafter referred to as FI system) is making its appearance as an effective device to reduce emissions while improving fuel economy by precisely controlling the air-to-fuel ratio.
Fuel injectors and fuel pumps currently used in small motorcycle FI systems were originally derived from multi-cylinder engine automobile and large motorcycle FI system components, and therefore have not been necessarily suitable for small motorcycle application.
Recently, the authors have created a compact yet efficient fuel injector and fuel pump for specifically for application in small motorcycle FI systems, compatible for various engine displacements and configurations
For the fuel injector, the spray form was optimized using fuel spray simulation software and the appropriate magnetic circuit was achieved through the implementation of a new magnetic material specification. Thus, a compact, easy-to-mount injector, applicable for engine displacements from 50 to 900 cm3, was developed.
For the fuel pump, efficiency was improved by 4% by the improvement of pump motor efficiency and the optimization of pump rotor shape. As a result, while maintaining the same size as a conventional fuel pump, the power consumption was reduced by 25%.