Electronic Direct Fuel Injection System Applied to an 1100cc Two-Stroke Personal Watercraft Engine

Direct injection has been considered the most effective approach to overcome the inherent short-circuiting of fuel in a two-stroke engine. A practical application of this technology on an 1100cc personal watercraft (PWC) engine is described. The experimental results show a drastic improvement in the engine emissions and fuel economy while maintaining good output performance and drive-ability of the PWC tested. The all-electronic, direct fuel injection engine has demonstrated a 76.3% reduction in hydrocarbon (HC) emissions and 43.03 g/kW-h HC plus oxides of nitrogen (NOx) emissions. This HC + NOx level meets the emission standards applicable to the 2006 model year set by the Environmental Protection Agency (EPA) for new gasoline spark-ignition marine engines.

Finally some considerations on extending the technology to include combustion control in the areas of both air and spark management, are recommended.