Kawasaki Z1

The Kawasaki Z1 is a Japanese motorcycle introduced in 1972, powered by an air cooled 903cc double overhead cam inline four cylinder engine. Kawasaki developed it after learning that a rival manufacturer was about to release its own four cylinder machine, redesigning the engine at speed to beat that competitor to market. On release it was the fastest production motorcycle available, and it established the double overhead cam inline four as the dominant engine layout for the Japanese superbikes that followed it through the 1970s and beyond.