Kawasaki Z1

Last updated
Kawasaki Z1
1972 Kawasaki Z1
ManufacturerKawasaki Heavy Industries, Ltd.
Also calledKawasaki 900 Super Four [1]
Production1972–1975; 85,000 units (est.) [2]
SuccessorKawasaki Z900 [3]
Class standard
Engine DOHC 903 cm3 (55.1 cu in) air-cooled, inline-four [2]
Bore / stroke 66 mm × 66 mm (2.6 in × 2.6 in)
Top speed130–132 mph (209–212 km/h) [4] [5] [6]
Power 82 PS (81 hp) at 8500 rpm [1] [5]
Torque 54.2 lb⋅ft (73.5 N⋅m) at 8500 rpm [4]
Ignition type Battery
Transmission 5-speed
Frame type Full duplex cradle
Suspension F: Telescopic, R: Swing arm
Brakes F: 11.5 in (290 mm) disk (optional 2nd disk)
R: 7.9 in (200 mm) drum [7]
Tires F: 3.25-19, R: 4.00-18
Wheelbase 1,490 mm (59 in)
DimensionsL: 2,200 mm (87 in)
W: 685 mm (27.0 in)
H: 1,170 mm (46 in)
Weight510 lb (230 kg) [1]  (dry)
542 lb (246 kg) [8]  (wet)
Fuel capacity18 L (4.0 imp gal; 4.8 US gal)

The Kawasaki Z1 is a four-cylinder, air-cooled, double-overhead camshaft, carbureted, chain-drive motorcycle introduced in 1972 by Kawasaki. Following the introduction of Honda's CB750 in 1968, the Z1 helped popularize the in-line, across-the-frame four-cylinder, [9] a format that became known as the Universal Japanese Motorcycle or UJM.


The Z1 was noted for being the first large-capacity Japanese four-cylinder motorcycle to use the double-overhead-camshaft system on a production motorcycle. When it was introduced, only the MV Agusta 750 S used this system; it was a very expensive limited-production machine, as opposed to the Kawasaki which was less than half the price. [8] [10]

Marketed variously as the Z1-900, 900 Z1 or 900 S4 ("Super Four"), the Z1 was the first of Kawasaki's Z models. [3] [4] [11]


The Kawasaki Z1 was developed under the project name "New York Steak". [9] [10] In the late 1960s Kawasaki, already an established manufacturer of two-stroke motorcycles, had begun prototyping a 750 cc four-cylinder four-stroke sports motorcycle [2] working with McFarlane Design in 1969 to develop the bike's overall appearance. [12] When Honda introduced the CB750 to the market first, Kawasaki postponed the Z1's release until its displacement could be increased to 903 cc and the motorcycle could be marketed in the 1000cc-class. [2]

Z1 production began in 1972 as the most powerful Japanese 4-cylinder 4-stroke ever marketed. [7]

In 1972, the Z1 set the world FIM and AMA record for 24-hour endurance on the banked Daytona racetrack, recording 2,631 miles at an average speed of 109.64 mph. Writing in 1976, LJK Setright commented that this record was only 0.36% faster than the previous figure set in 1961 at Montlhéry, France, by a team using a modified BMW R69S, particularly the engine. [13] Also at this time at Daytona a one-off Z1 ridden by Yvon Duhamel that was tuned by Yoshimura set a one-lap record of 160.288 mph. [14] Setright commented that this achievement, using a 100-bhp output engine, was reflective of the progress made in a dozen years. [13]

The Z1 had full instrumentation and an electric start, produced 82 bhp and had a maximum speed of 130 mph to 132 mph (210 km/hr). [5] It met with positive reviews from the motorcycle press, who praised its smoothness, damped vibration, easy starting (kick-start and electric were both fitted), straight-line stability and linear acceleration. Steering was accurate and the bike handled well, but testers said the rear tire, chain and rear shocks all wore out quickly. [2]

The Z1 was awarded the MCN 'Machine of the Year' accolade each year from 1973 to 1976 (an award resulting from a readers' opinion-poll run by UK weekly publication Motorcycle News) [15] The Society of Automotive Engineers of Japan (in Japanese) includes the 1972 Z1 as one of their 240 Landmarks of Japanese Automotive Technology. [1]

1974 Kawasaki Z1A on display at the Barber Vintage Motorsports Museum 1974 Kawasaki 900 Z1.jpg
1974 Kawasaki Z1A on display at the Barber Vintage Motorsports Museum

Design changes

The basic design of the Z1 remained relatively unchanged until 1975, when the 903 cc "Z1-B" was introduced, with changes including increased power output, improved suspension, and a stiffer frame. The automatic chain oiler was deleted, the styling was revised – essentially paint scheme and side-panel nomenclature – and the braking was improved.

Follow-up series

In 1976 the Z1 was replaced by the Kawasaki KZ900 in the U.S. and Z900 in other markets. [7] This was succeeded by the 1977 Kawasaki Kz1000 ("Z1000") [11] and Kawasaki Z1000 Z1-R, and in 1984 by the Kawasaki Z1100R.

In 1983, Kawasaki won back the crown of the fastest production bike with the Kawasaki GPZ900R which had some other references to its predecessor like the model designation code ZX900, four cylinders and 900 ccm.[ citation needed ]

The 1991 Kawasaki Zephyr series copied a lot of the design of the first naked Z1, as did the Z1000 in 2003. It received updates in 2007 and a major redesign in 2010. [11]

In 2018 Kawasaki released the Z900RS. This bike is a tribute to the original Z-1, but with such modern features as water cooling, fuel injection, a 6-speed transmission, upside-down front forks, mono-shock rear suspension, ABS brakes, and traction control.

See also

Related Research Articles

Honda CB750

The Honda CB750 is an air-cooled, transverse, in-line four-cylinder engine motorcycle made by Honda over several generations for year models 1969–2003 as well as 2007 with an upright or standard riding posture. It is often called the original Universal Japanese Motorcycle (UJM).

AMA Superbike Championship

AMA Superbike Championship is an American motorcycle racing series that has been run every year beginning in 1976. For most of its existence it has been considered the premier motorcycle road racing series in the United States. It is sanctioned by the AMA American Motorcyclist Association since its inception, and the promotion of the series has been licensed to several organizations over the years. Since 2015 the series has been run and promoted by MotoAmerica, who also manage several other AMA professional road racing championships, including the popular 600cc Supersport class.

Kawasaki GPZ900R Kawasaki motorcycle

The Kawasaki GPZ900R is a motorcycle that was manufactured by Kawasaki from 1984 to 2003. It is the earliest member of the Ninja family of sport bikes. The 1984 GPZ900R was a revolutionary design that became the immediate predecessor of the modern-day sport bike. Developed in secret over six years, it was Kawasaki's and the world's first 16-valve liquid-cooled inline four-cylinder motorcycle engine.

Universal Japanese Motorcycle 70s motorcycles that revolutionized the US bike market

Universal Japanese Motorcycle (UJM) is a US motorcycling media term for a general-purpose style of Japanese standard motorcycle that revolutionized the industry and made motorcycling in America more accessible during the 1970s and 1980s. By around 1990 its popularity began to wane as the market fragmented into more specialized designs.

Kawasaki Z650

The Kawasaki Z650 was produced as a 652 cc (39.8 cu in) standard motorcycle by Kawasaki from 1976 until 1983. It had a four-cylinder four-stroke, DOHC, air-cooled, wet sump engine positioned across the frame with two valves per cylinder and a five-speed gearbox. Designed as a middleweight version of the Kawasaki Z900, the similar-styling had "an attenuated version of the traditional Kawasaki tail fairing". It competed in the market against the smaller SOHC Honda CB650. The Z650 was the epitome of the "Universal Japanese Motorcycle" (UJM).

Honda CBX sports motorcycle manufactured from 1978 to 1982

The Honda CBX sports motorcycle was manufactured by Honda from 1978 to 1982. With a 1047cc inline six-cylinder engine producing 105 bhp (78 kW), it was the flagship of the Honda range. The CBX was well-received by the press, but was outsold by its sibling introduced in late 1979, the Honda CB900F.

Motorcycle engine Engine that powers a motorcycle

A motorcycle engine is an engine that powers a motorcycle. Motorcycle engines are typically two-stroke or four-stroke internal combustion engines, but other engine types, such as Wankels and electric motors, have been used.

Kawasaki Zephyr

The Kawasaki Zephyr is a range of retro-styled naked superbikes made in the 1990s in Kawasaki's Z series. All models have transverse air-cooled dual overhead camshaft inline-four engines. There were a number of Zephyr models, in four engine capacities, 400, 550, 750, and 1,100 cc.

BSA Rocket 3/Triumph Trident 1960s/1970s British motorcycle made by Triumph Engineering, Meriden

The Triumph Trident and BSA Rocket 3 was a technically advanced, high-performance roadster motorcycle made by Triumph Engineering and BSA from 1968 to 1975, and sold under both the Triumph and BSA marques. Alongside the Honda CB750, and later the Kawasaki triples, it brought a new level of sophistication to street motorcycles, marking the beginning of the superbike era. The Honda CB750 overshadowed the Trident to be remembered as the 'first superbike', in spite of the Triumph Trident actually debuting before the Honda by a few weeks.

Rickman Motorcycles

Rickman Motorcycles was a British, independent motorcycle chassis constructor established by brothers Derek and Don Rickman. The firm manufactured motorcycles from 1960 through to 1975.

Kawasaki Z1000

The Kawasaki Z1000 is a four-cylinder motorcycle introduced in 2003 with streetfighter or standard styling. The Z1000 was first introduced in 1977 superseding the previous 903 cc capacity Z1/Z900.

Kawasaki triple

The Kawasaki triples were a range of 250 to 750 cc motorcycles made by Kawasaki from 1968 to 1980. The engines were air-cooled, three-cylinder, piston-controlled inlet port two-strokes with two exhaust pipes exiting on the right side of the bike, and one on the left. It was the first production street motorcycle with capacitor discharge ignition (CDI). Right from the first triple model, the 1968 Mach III H1 500 cc, it was a sales success that gained a reputation for almost unmatched acceleration as well as an air of danger for inexperienced riders trying to cope with the bike's increased power to weight ratio over any previously available stock motorcycles.

Kawasaki Z1300

The Kawasaki Z1300 is a standard motorcycle unusual for its large-displacement 1,300 cc straight-six engine made by Kawasaki from 1979 to 1989.

Kawasaki Kz1000

The Kawasaki Kz1000 or Z1000 is a motorcycle made in Japan by Kawasaki, manufacturing commenced in September 1976 for the 1977 model year. The Z1000A1 was an upgraded model to replace the 1976 Kawasaki KZ900 (Z900), which in turn replaced the Z1 launched in 1972 in the Z series. It has an inline-four cylinder engine and a 5-speed transmission, in a 'one down and four up' configuration. Producing about 90 hp, it was one of the fastest production motorcycles of the era. The police model continued in production until 2005.

The Honda CB900F is a Honda motorcycle made in two iterations which appeared some twenty years apart. Both generations of the CB900F are straight four-cylinder four-stroke 900 cc (55 cu in) roadsters.

Meguro motorcycles

Meguro motorcycles were built by Meguro Manufacturing Co motorcycle works (目黒製作所), founded by Hobuji Murato and a high-ranking naval officer, Takaji Suzuki, in 1937. One of the first Japanese motorcycle companies, it became a partner of Kawasaki Heavy Industries Ltd, and was eventually absorbed. Named after a district of Tokyo, Meguro had its roots in Murato Iron Works, which was established in 1924. Meguro Seisakusho, which had once developed a copy of a Harley-Davidson V-twin, was established to design and build gearboxes for the nascent Japanese motorcycle industry. Abe Industries, which had once produced its own motorcycle, merged with Meguro in 1931. The brand is being revived by Kawasaki with a new K3 model to be introduced in Japan on February 1, 2021.

Forced induction in motorcycles is the application of forced induction to a motorcycle engine. Special automotive engineering and human factors considerations exist for the application of forced induction with motorcycles, compared to other forms of motorized transportation.


  1. 1 2 3 4 "Kawasaki 900 Super Four". 240 Landmarks of Japanese Automotive Technology. Society of Automotive Engineers of Japan, Inc. Retrieved 6 November 2013. Journalists and riders called it the king of motorcycles, and it gained a reputation as a super sport model all over the world. The Super Four boasted high performance and quality. This best-selling motorcycle won many prizes around the world within only six months of its release.
  2. 1 2 3 4 5 Siegal, Margie. "1973 Kawasaki Z1: King of the Road". Motorcycle Classics May/June 2006. Retrieved 10 December 2012.
  3. 1 2 Ker, Rod (29 September 2008). "Kawasaki Z1: remembrance of things fast" . The Telegraph. Archived from the original on 2022-01-12. Retrieved 6 November 2013. While I don't have a clue what I was doing when Kennedy was shot, I can clearly remember the first time I saw a Kawasaki Z1. In 1974, this four-cylinder, 903cc, 81bhp, 132mph projectile was the fastest, most glamorous thing on two wheels. Only a handful had been sold in Britain, and only the lucky few had even seen one.
  4. 1 2 3 Newland, Martin (5 May 2004). "Retro rocket" . The Telegraph. Archived from the original on 2022-01-12. Retrieved 6 November 2013. The 1973 Kawazaki Z1 was the world's first superbike and its spiritual successor, the Z1000, relies on the same stripped-down looks and raw, steady power for its appeal. It's the ideal big boy's toy…
  5. 1 2 3 Walker, Mick (2 October 2006). Motorcycle: Evolution, Design, Passion. The Johns Hopkins University Press. p. 150. ISBN   978-0-8018-8530-3.
  6. Brown, Roland (2006), The Ultimate History of Fast Motorcycles, Bath, UK: Parragon, pp. 214–215, ISBN   1-4054-7303-7
  7. 1 2 3 Williams, Greg. "Son of Z1: The 1976 Kawasaki Z900". Motorcycle Classics September/October 2012. Motorcycle Classics. Retrieved 10 December 2012.
  8. 1 2 John L. Stein (1 August 2010). "Then & Now: Kawasaki Z1000 vs. Z1". Motorcyclist . Source Interlink Media. Retrieved 6 November 2013. During its development, the 1973 Kawasaki Z1 was codenamed New York Steak. And it was just that: 23 percent larger than Honda's benchmark 750cc Four, it busted open the fledgling superbike ranks and would soon make its impact in racing, too. Blasphemously heavy at 542 lbs. wet, the Z1 did everything to excess, from its audacious 903cc DOHC four-cylinder engine to its roomy cockpit, enormous linkless chain with proprietary oil pump, and quartet of chrome-plated megaphones.
  9. 1 2 Melling, Frank (27 July 2007). "Memorable Motorcycle Kawasaki Z1". Motorcycle USA. Retrieved 6 November 2013. It's time to correct one of the popular myths which is becoming ever more prevalent in the motorcycling world. Thus: 'When Honda launched its 750 '4' in 1968, the biking world fell on its knees and worshipped the new arrival.'
  10. 1 2 Kuhn, Fran (24 February 2009). "Kawasaki 903 Z1 - Bikes of the 70's". Motorcyclist . Source Interlink Media. Retrieved 6 November 2013. By now you must've already heard the story of how the Z1--code-named 'New York Steak' for some ridiculous reason or other by Kawasaki--was originally intended to be a 750, and of how Kawasaki brass nearly suffered a corporate coronary when Honda introduced its own 750cc four-cylinder in late 1968. Kawasaki, cornered, had no choice but to make the Z1 even bigger and stronger and tricker than the mighty CB750.
  11. 1 2 3 "40 years of Kawasaki's 'Z' sleds". Independent Online. Independent Newspapers (Pty) Limited. 5 June 2012. Retrieved 6 November 2013. …the DNA of the 1972 Z1 is still clearly discernable in the Kawasaki's current litre-class musclebike, the Z1000.
  12. "The Kawasaki Prototype". Motorcycle Classics September/October 2006. Retrieved 10 December 2012.
  13. 1 2 Motorcycles, LJK Setright, 1976, pp.138-143 Weidenfeld & Nicolson London. Accessed 29 June 2019
  14. Boehm, Mitch (May 5, 2016). "The Legendary Kawasaki Z1". Motorcyclist . Retrieved June 1, 2016.
  15. "Kawasaki official site" . Retrieved 2013-04-06.

Additional resources

Preceded by Fastest production motorcycle
Succeeded by