Kawasaki’s 1972 Z1 motorcycle had an engine displacement of 903 cc.
The Z1 was Kawasaki’s flagship four-cylinder standard motorcycle and was developed partly in response to Honda’s CB750. Its air-cooled, double-overhead-camshaft engine used four cylinders and became one of the most influential Japanese motorcycle engines of the 1970s.
The Z1 was often described as a 900-class motorcycle, but its exact displacement was 903 cubic centimetres. This is a common point of confusion because the model name and rounded class description do not state the precise engine size.
Kawasaki later developed related Z-series models, including the Z900, but the original Z1 remains specifically associated with the 903 cc engine. Its combination of performance, reliability and four-cylinder smoothness helped establish Kawasaki as a major global motorcycle manufacturer.