In Brazil the market for small motorcycles had steadily increased during the last decade. Nowadays about 2 million units are produced every year. Market forecasts show that this trend will remain for many years.
The amount of pollutant gases emitted by the small motorcycles fleet, begin to be significant. For this reason, the government established emissions laws for motorcycles to be effective since 2003.
This law will become stricter over the years up to the point that the use of electronic fuel injection systems for small motorcycles will be a convenient way to adhere to the law.
The cost of ethanol fuel is almost half of the gasoline and therefore is the fuel of choice of the majority of drivers. Moreover the use of ethanol is far better than gasoline in terms of emission of green house effect gases.
The current motorcycle's fuel delivery systems are not suited to use ethanol. The above reasons motivated the development of a flex fuel engine management system for small motorcycles.
With this system, a motorcycle could run with any mixture of ethanol and gasoline, delivering the best performance and fuel economy all the time, while adhering to the emission's laws.
Compared to the carbureted version, the motorcycle using electronic fuel injection has superior fuel consumption, driveability, idle and cold start behaviors. This paper will present this system in detail.