A Distinctive Liquid-Cooled V-Twin
Yamaha Motor USA identifies the XZ550R Vision as a two-year U.S. model offered for 1982 and 1983. Yamaha described its power unit as a liquid-cooled, double-overhead-cam, 552cc, 70-degree V-twin four-stroke. The factory parts catalogs also separate its carburetor, water-pump and radiator, balancer and shaft-drive systems. That combination makes exact model identification more useful than shopping from engine size or appearance alone.
Yamaha’s U.S. parts diagrams identify the 1982 motorcycle as XZ550RJ and the 1983 motorcycle as XZ550RK. These are complete model-year catalog designations, not three unrelated motorcycle families called XZ550R, XZ550RJ and XZ550RK. Yamaha also produced the separate XZ400 for other markets. The shared XZ name does not establish interchange between the 400 and 550, or between every 1982 and 1983 component.