The Kawasaki Z1 is one of the most important Japanese motorcycles of the 1970s, and a favourite of collectors. Its story starts with a rival's launch.
The story
Kawasaki developed its four-cylinder machine under the project name "New York Steak". It had planned a 750 cc bike, but when Honda released the CB750 in 1968, Kawasaki held back the Z1 until its capacity could be raised to 903 cc. The Z1 was introduced in 1972 with a DOHC 903 cc air-cooled inline four, 82 bhp at 8,500 rpm, and a top speed of about 130 to 132 mph.
The milestones
- 1972 to 1975. The Z1 was produced, with an estimated 85,000 built. It was sold under names such as Z1-900, 900 Z1 and 900 S4.
- The fastest production bike. The Z1 held the title of the fastest production motorcycle from 1973 to 1975, until the Ducati 900SS succeeded it.
- 1976. The Z1 was replaced by the KZ900 in the US and the Z900 in other markets. It was the first of Kawasaki's Z models.
- Before the Z1. Kawasaki's earlier performance machines were two-strokes, such as the 500 cc triple Mach III of 1969.
What to know when buying
- Z1 or Z900. They look similar and are priced very differently. Check the year, the frame number and the engine number against the papers. See frame and engine numbers.
- Originality. Many Z1s were modified for the road and the strip. Original paint, original exhaust and a documented history add the most value. See condition grades.
- Restored or survivor. A restored bike can be excellent, but ask what was replaced. See originality and patina.
- Papers. Many Z1s have been imported. Check the registration and the import papers. See papers and proof of ownership.
Parts and community
Parts supply for the Z1 is good thanks to reproductions and specialists, though original parts are costly. See finding parts.
