Kawasaki Z1 900


Make Model

Kawasaki Z 900




Four stroke, transverse four cylinder, DOHC, 2 valve per cylinder.


903 cc / 55.1 cu-in
Bore x Stroke 66 x 66 mm
Cooling System Air cooled,
Compression Ratio 8.5:1
Lubrication Wet sump, trachoid pump
Air Filtration Treated synthetic fiber


4x 26mm Mikuni VM26SS


Mechanical breaker dual lead coil 
Starting Electric

Max Power

81 hp / 59 kW @ 8500 rpm

Max Torque

73.5 Nm / 52.8 lb-ft  @ 7000 rpm
Clutch Wet, multi-plate


5 Speed 
Final Drive Chain
Primary Drive Straight cut gears
Gear Ratio 1 st 12.05:1 2nd 8.34:1 3rd 6.36:1 4th 5.25:1 5th 4.63:1
Double tubular steel cradle

Front Suspension

36mm Telescopic forks

Rear Suspension

Dual shock, 5-way preload adjustment

Front Brakes

2x 296mm discs 

Rear Brakes

200mm drum

Front Tyre


Rear Tyre

Tral 3.75 in.
Dimensions Length  2209.8 mm / 87.0 in.
Wheelbase 1498.6 mm / 59.0 in
Handlebar Width 818 mm  / 32.2 in.
Seat Height 812.8 mm  / 32.0 in.
Ground Clearance 170 mm / 6.75 in.

Dry Weight

230 kg / 507 lbs
Wet Weight 248 kb / 548 lbs

Fuel Capacity 

18 Litres / 4.7 gal

Consumption Average

48 mpg
Braking Distance 30 mph - 0 25.00 ft.
Braking Distance 60 mph - 0
103.00 ft.
Acceleration 0-30 mph 2.1 sec
Acceleration 0-60 mph 5.1 sec

Standing ¼ Mile  

13.7 sec / 94.65 mph

Top Speed

120 mph


1976 Z900-A4

FRAME NUMBER: Z1F-085701 >
Major changes for this model included colour and marking, different side panels and badges, airbox, twin front brakes, locking fuel cap, three way fuse system, hazard warning lights, audible flasher indicator, square tail light, improved instrument cluster and a change to smaller 26 mm carbs. Power was down to 81 bhp but the Z900 was a much better bike to ride. A few extra models
rolled off the American production line in Lincoln in 1977 known as the KZ900-A5.


The original 903cc Kawasaki, introduced to Europe in 1972 as the Z1, had its first major update four years later. Withdrawn late in 1975, it reappeared the following year with a new title, Z900, and sporting improvements to justify a useful price increase.

The most noticeable of these was the addition of a second disc brake to the front wheel, previously obtainable as a pricey extra for the Z1. The use of a thinner disc and smaller caliper meant that total weight of the twin units was not much above that of the Z1's single brake. Other modifications were stiffer rear suspension, audible 'bleepers' for the direction

indicators, a hazard-warning facility metal flake finish, in various colours 1Z the 3.7 gallon fuel tank. ' m

As for the engine, that remained basicattv undisturbed; smaller carburettors and more efficient muffling in the exhaust system, had helped to reduce power bva mere horsepower to 81 bhp, and peak torque had moved 500 rpm up the scale to 7,500rpm, but the big Kawasaki, in the mid-1970s was still unchallenged as the fastest standard roadster on offer.



Kawasaki started production of parts for the Z900-A4 in mid 1975 ready for the 1976 model year.
The '4' of the A4 signified the fourth production year of the 903cc series.

Kawasaki was the first Japanese motorcycle manufacturer to set up a manufacturing plant in the USA.
This plant was in Lincoln, Nebraska and the first Kawasaki to be assembled there was the KZ400 twin.

Kawasaki exported parts from Japan to the USA and the assembly of the American model KZ900-A4 started at the Lincoln plant in June 1975.

The 1976 model Kawasaki Z900-A4 for the UK and European market was first produced in October 1975.

The Z900-A4 and KZ900-A4 were badged as Z900 and KZ900 respectively.

With the introduction of the Z900, although the basic shape remained the same as the Z1 models, there were several styling changes along with some important mechanical improvements.

The engine of the Z900 was produced in a bare aluminium finish as with the Z1A and Z1B. Redesigned and smaller 26mm Mikuni carburettors were used in an effort to improve mid range rideability.

This did reduce the maximum power to 81 bhp and the top speed slightly in comparison to the earlier Z1 models.

The electrical system was redesigned and now featured a three way fuse system.
The turn signal indicators featured an audible tone. However, many owners thought this to be an embarrassment and disconnected it.
There was a Hazard Warning Lights feature with the switch fitted to the handlebar below the tachometer.
The frame was now manufactured using thicker walled tubing to reduce flexing in order to improve handling.
The front forks were also redesigned. The reflectors previously fitted to the front fork legs of US variants of the Z1 were now relocated to each side of the frame just below the front of the fuel tank.
Twin front disc brakes with newly designed calipers were standard.

The American KZ900 only had a single disc brake on the left hand side with twin discs as an option.

The front wheel hub was redesigned and was no longer painted black.

The rear drum brake remained on all models. 
Although much thinner than the stripes on the original Z1, the pinstripes on the Z900 tailpiece followed a similar pattern to the Z1 in that they ran along the bottom edge of each side of the tailpiece and then curved up and over the top at the rear to meet in the middle.
The tailpiece itself was now a slightly different shape at the rear as it now housed a "squared off" tail light.

The tail light on US models featured a reflector on each side. The reflectors that had previously been featured on the outsides of the rear shock absorbers on all US variants of the Z1 were therefore no longer required.

The passenger grab rail on US models was similar to the ones fitted to earlier Z1 models and the rear turn signals were fitted to the frame, however the UK model had brackets welded to the grab rail to which the indicators were fitted.
Each letter and number of the badge was in white with a chrome surround and set on a black backplate. The letters were slightly smaller than the numbers.

The instruments of the Z900 were redesigned with a more modern look to the console between the speedometer and the tachometer.

The STOP LAMP feature was relocated from the tachometer to the centre console which featured warning lights from top to bottom for NEUTRAL, HIGH BEAM, OIL and STOP LAMP.

Left and right turn signal lamps were positioned either side of the ignition key.
As with the Z1B, the speedometer was calibrated to 160mph in 10mph increments.
Source kawasakiz1.com