Abstract
Air-cooled small gasoline engines used for motorcycles are utilized for personal mobility. They are better in fuel economy than automobiles and have an advantage in an environmental impact. Piston friction reduction is effective for further fuel economy under partial load conditions. Additionally a piston of such an engine must be designed to have durability and reliability under a wide speed range. Therefore piston friction measurement was carried out for an air-cooled small gasoline engine. Piston friction was successfully measured under 5200 rpm. Measured results suggested that oil was starved at mid-stroke under high speed condition.
