Carole Nash
Content Writer
Published: 19th June 2008

Here’s one of the all time greats, the bike they called the king of the Superbikes…

Here’s one of the all time greats, the bike they called the king of the Superbikes, way back in the 70s.kawasaki z1

Originally designed to be a 750cc four stroke, four cylinder machine, Kawasaki Heavy Industries went back to their drawing boards after Honda shook up the world of motorcycling in 1969 with their CB750. Kawasaki just went one better, by creating a 903cc sized roadburner, with handlebars wider than Status Quo’s flares and a top speed approaching 130mph.

High speed handling which could be diplomatically described as interesting only added to the appeal of the Z1 for many bikers back in 1973. The Z1s durable 83bhp motor became the power unit for endurance racers, world record speed attempts, and was even turbo charged – by Kawasaki themselves.

It was called The King, and for years Kawasaki’s Z1 had no pretenders to its crown. With an electronically tested top speed of 134 mph in 1973, Kawasaki’s entry into the big four-cylinder bike market had an impact few have ever matched.

Its roots go back to 1967, when Kawasaki’´s rapid two-strokes were frightening unwary riders with their wheel-standing habits and offending bureaucracy with their blue exhaust fumes. America was a vital market for the company, and was known to be planning legislation to control exhaust pollution, so engineer Gyoichi Inamura was appointed head of a team developing a new fourstroke model. Their answer was a 750cc four cylinder, but Honda announced their own 750 Four in 1968. The goalposts in the game of international success had been moved.

Kawasaki’s answer, codenamed T103, was running by 1970. By May 1972 production was under way and at the Cologne Show that September the Z1 was launched. It came with 82bhp at 8.50,00 rpm, a top speed that made it the fastest production bike in the world, and it would purr through town at a whisper with no more than 83 decibels coming from the four upswept silencers. Available in a combination of Candy Apple and Orange, the black cylinder block with the tips of its fins polished alloy highlights, a proud `900 Double Overhead Camshaft´ badge on the sidepanels, it was a real stunner. In Britain, it was yours for £1088, if you were lucky enough to afford the payments. Rich people could, while poorer but enthusiastic people said they would, whatever sacrifice they had to make. Some dug deeper for the optional second front disc, that didn´t become standard until the 1976 Model KZ900-A4.

It was not the best handling bike on the road, and when MCN´s tester rode it through the speed trap at 134 mph it weaved and wobbled so much the timekeeper thought he was about to witness the fastest leg-off in the paper´s history. But the bike came back under control to an enthusiastic write-up. That year MCN´s readers voted the Z1 MCN Motorcycle of the Year.

The engine became the definitive `bullet proof´ power unit. In 1973, at Daytona Speedway, Florida, a Z1 set a class world record of 150.8 mph for ten kilometres and went on to average 109.6 mph for 24 Hours, another world record. Drag racers and sprinters, led by Holland´s importer Henk Vink, supercharged the engine to dominate their own sport. British chassis makers like the Rickman Brothers produced frames to tame the 82 bhp power and make it the fastest on straight roads or twisties.

The 903cc Z1 evolved, with minor modifications and colour and styling changes, from its 1973 form to the A4 version of 1976. The most obvious change in its successful life was a change to natural alloy cylinder finish on the 1974 Z10A version. For 1977 it was replaced by the Z1000, but the lean, mean Z1 is still remembered as the real thing. The true King.

by Jim Reynolds.

Get Kawasaki motorcycle insurance for the kawasaki z1.

Vital Statistics

Engine Straight four-cylinder, double overhead camshaft, all alloy. 66mm bore x 66mm stroke,
cc 903
Claimed power (bhp)
Compression ratio 8.5 to 1
Transmission Five-speed constant mesh gearbox, in unit with engine. Primary drive by gear direct to clutch body, secondary drive by chain with automatic lubrication.

Cycle parts
Welded tubular steel duplex cradle frame. Telescopic front forks and swinging arm rear suspension with two adjustable shock absorbers.
Single 11.6 inch (296mm) hydraulic front disc brake (optional second disc available) and 7.9 inch (200mm) single leading shoe drum at rear.

Standing start 440 yards (400m) 12.0 seconds @ c.110mph (177 km/hr) terminal speed. 40mpg cruising at speed, more ridden gently.
Top speed 130 plus mph
Fuel capacity

Buying Info
Current price new £1088