Kawasaki Z1

From CycleChaos
Jump to navigation Jump to search
Kawasaki Z1
Manufacturer Kawasaki
Also called Z1, Z900, KZ900
Production 73-75
Successor Kawasaki KZ900A
Engine 903cc air-cooled DOHC inline-four
Bore / Stroke 66 x 66mm
Compression ratio 8.5:1
Top speed 130mph
Horse Power 82 HP @8,500 rpm
Fuel system 4x Mikuni VM 28mm carburetors
Sparkplug B8ES 73-75
Battery 12N14-3A 73-75
Transmission 5-Speed Return Shift
Frame type tubular steel, double cradle
Suspension Front: telescopic forks
Rear: swingarm / twin shocks
Front Tire 3.25-19 73-75
Rear Tire 4.00-18 73-75
Fuel consumption 45 mpg (average)
Related Kawasaki KZ900A
Kawasaki KZ1000A
Competition Honda CB750K
Triumph Trident
Suzuki GT750
Manuals Service Manual
Brochures · Reviews · Ads · Videos

The Kawasaki Z1 is a high performance superbike motorcycle produced by Kawasaki from 1973 to 1975.


Kawasaki's earlier two and three-cylinder bikes such as the H1, and H2 had bestowed Kawasaki with a high performance image. But these bikes had known problems: excessive fuel consumption, noise, vibration, and less than perfect handling. Their sparse comfort relegated them to the role of street racer. Kawasaki engineers had outlined these limitations of their two-stroke triples as early as 1967. This led to the beginning stages of planning a four-stroke super cruiser in the mold of the 1000cc Vincent, that could be ridden in any situation, and would be "THE" bike all experienced riders lusted after.

New York Steak

The Kawasaki Z1 gave the world its first true superbike. Introduced in late 1972, the Z1 was Kawasaki's first four-cylinder, four-stroke motorcycle. During its planning stages it was called the codenamed the T-103 and nicknamed the 'New York Steak'. Before the introduction of the Honda CB750K to the world at the October 1968 Toko Motor Show, Kawasaki had already sent a mock-up double overhead camshaft Z1 to US Kawasaki's Sam Tanegashima. Honda's head start caused Kawasaki to be patient and carefully judge the revolutionary bike's impact.


The Z1 became the "King of the Road" and an industry leader; as the first production motorcycle to bring such high performance and prestige to the general public. Cycle Magazine recorded a standing quarter mile time of 12.83 seconds @ 101.7 mph.

Impact on the industry

All other manufacturers had to change their mindset to keep up with popularity of this motorcycle. By the end of the decade all Japanese manufacturers had developed machines to rival the Z1 which were almost direct clones of its engine configuration and integral body panels.

These bike wars directly lead to the demise of the flagging BrItish motorcycle industry.The American motorcycle industry (mainly Harley-Davidson) was also on its last legs and was only saved by radical restructuring and inventive financing.

Design changes

The basic design of the Z1 remained relatively unchanged until the early 1980s with the exception of increased engine displacement (1015cc). This model is also the basis for the motorcycle used by most police forces across the United States to this day.


Only recently (2005) did Kawasaki announce that it would discontinue production of the police model, 25 years after the production on the consumer model and 32 years after its introduction.

1973 Z1

1973 Kawasaki Z1 900
1973 Kawasaki Z1 in Candy Brown
1973 Kawasaki Z1 in Candy Brown
1973 Kawasaki Z1 in Candy Brown

  • Color
    • Fuel Tank: Candy Yellow/Green, Candy Orange/Brown (UK & Europe); Candy Orange/Brown (US)
    • Front Fender: Chrome
  • Engine No.: Z1E000001-
  • Frame No.: Z1F-000001-
  • Parts Catalog No.: 99997-603, (E) 99997-608S
  • Owner's Manual No. : 99997-800
  • Shop Manual No. : 99997-700

The First Z1.

1974 Z1A

1974 Kawasaki Z1A 900
1974 Kawasaki Z1A in Maroon
1974 Kawasaki Z1A in Brown
1974 Kawasaki Z1A in Brown

  • Color
    • Fuel Tank: Candy Tone Brown/Orange, Candy Tone Yellow/Green
    • Front Fender: Chrome
  • Engine No.: Z1E020001-
  • Frame No.: Z1F-020001-
  • Parts Catalog No. : 99997-627, (E) 99997-627-01S
  • Owner's Manual No. : 99997-808, (E) 99997-021, (F) 99983-009, (I) 99983-010, (W) 99983-011
  • Shop Manual No.: 99997-700

For 1974 Kawasaki changed the colors and markings, and the engine dropped the black paint to simply be an aluminum color. In mid 1974 there was a slight carburetor change to improve cold running. At the end of 1974 Kawasaki had produced over 80,000 units of the Z1 and Z2.

1975 Z1B

  • Color
    • Fuel Tank: Candy Super Blue, Candy Super Red
    • Front Fender: Chrome
  • Engine No.: Z1E047500-
  • Frame No.: Z1F-047500-
  • Parts Catalog No.: 99997-627-50S, (E) 99997-627-51S
  • Owner's Manual No.: 99997-832
  • Shop Manual No.: 99997-700
  • Major Changes: Color and marking. Special chain provided with sealed-in grease. Automatic chain oiler discontinued.

Kawasaki dropped the automatic chain oiler in favor of an o-ring chain. The front forks received revised dampers and softer springs. To improve low speed running there was a new automatic ignition advance. Unlike on the trend with the H1 these changes didn't drop performance.

1976 Z1

The model designation was changed to KZ900A and started in 1976 with the KZ900-A4 model.