The Yamaha SR400 (1978–2021) and SR500 (1978–1999) are single-cylinder, air-cooled, two-passenger motorcycles manufactured in Japan by Yamaha Motor Company as a street version of the Yamaha XT500, with a standard riding posture and styling resembling the Universal Japanese Motorcycles of the 1970s. The two models differ by their engines: the SR400 engine has a lower displacement, achieved with a different crankshaft and shorter piston stroke and both models feature only kickstarting, i.e., no electric starter.
