Nowadays more than a million and half motorcycles are produced every year. In the metropolitan areas, the amount of pollutant gases emitted by the small motorcycles, begin to be significant. For this reason, the Brazilian government established emissions laws for motorcycles to be effective since 2003. Historically, 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 greenhouse effect gases. In 2009, flex-fuel motorcycles began to be sold to the public. As they lack a proper cold start system, when using only hydrous ethanol fuel (E100) and the ambient temperature is lower than 15 degrees Celsius, the motorcycle is difficult to start and does not have a good driveability. As mitigation action, the maker's advice is to fill the tank with at least 20% gasoline. This poses an inconvenience to the driver and avoids the optimal fuel cost. In order to solve this, a heated injector cold start system is proposed to flex-fuel motorcycles. The heated injector is provided with a heater at its tip, which is used to heat the fuel before the engine is cranked and for some time while the intake valve reaches its operational temperature. On top of that, using heated fuel might reduce the emission of HC and CO; minimizing the cost of exhaust gas after-treatment. It is also important to reduce emissions of unburned ethanol to the atmosphere to minimize generation of troposphere ozone, which is a harmful gas to health. This paper will present this cold start system in detail, showing comparison data of engine performance, driveability and emissions.