How Much Horsepower Does The Kawasaki Z1 Have & How Fast Can It Go?

Kawasaki introduced the Z1 in 1973 as a return salvo to Honda, which had unleashed the CB750 and CR75 on the world a few years earlier. The two rivals are separated by Yamaha at the top of our rankings of the best motorcycle brands, based partly on the significance of their classic superbikes. The CB750's four-stroke, four-cylinder engine displaced 736 cubic centimeters and produced as much as 67 horsepower, but Kawasaki surpassed those numbers with the Z1. 

It had a 903 cubic centimeter four-banger that put out 82 horsepower and could carry its rider faster than 130 miles per hour, which was about markedly faster than its competitor from Honda. This advantage was partially creditable to the Z1's dual overhead cam architecture, which allowed for more robust interchange of fuel and exhaust than the CBR750's single-overhead cam build. Both bikes were gorgeous hunks of chrome, shiny paint and leather, but speed was king in the early '70s, and in that respect, Kawasaki had a clear advantage. 

[Featured image by Manju via Wikimedia Commons|Cropped and scaled|CC-BY SA 3.0]

The development of the Z1 began in 1967 under the direction of engine design head Gyoichi 'Ben' Inamura, who was instructed to build a 750 cubic centimeter motor. When Honda unveiled the CBR750 at the following year's Tokyo Motor Show, Kawasaki decided to break an unwritten agreement with its competitor with and build a bigger engine for the ZR1. For inspiration, company president Yoji Hamawaki reached across the Pacific Ocean and the breadth of the United States.  "We knew that in America the best meal on the menu was New York steak," he told Motorcyclist. "In our minds, the Z1 was going to be the best motorcycle we could make, the top of the menu." 

After some internal debate on what direction to take, Project New York Steak began and Kawasaki's design team started reconfiguring its 750 cubic centimeter engine. The team decided to emboss the letters "DOHC" on the engine's breaker points covers to further distinguish it from the Honda, and brought the new bike to Daytona for testing in the Spring of 1973. There, Kawasaki's team set a new 24-hour speed record of 109.641 miles per hour, which beat the old mark by almost 10 mph. It was one of more than 50 U.S. and world records broken in three days' worth of sessions, and immediately established the Z1 as a legend.