Improvement of Fuel Economy in a Four Stroke Spark Ignition Engine for a Small Motorcycle

For the purpose of reducing the fuel consumption of a motorcycle with a small-displacement, four-stroke spark-ignition engine, a compact combustion chamber was tried and the weight of the moving parts of the engine was reduced. As a result, the gas mileage under 30 km/h cruising condition was increased to 110 km/l with an improvement of 50% over a conventional motorcycle.