Kawasaki H2 Mach IV
|Parent company||Kawasaki Heavy Industries|
|Engine||748 cc Air-cooled, oil injected, 3-cylinder, transverse, two-stroke|
|Power||74 hp (55 kilowatts) @ 6800 rpm|
|Torque||7.9Kg-m @ 6500 rpm|
|Transmission||Chain driven, 5-speed 5up|
|Suspension||Inner spring telescopic front fork, three-position spring preload adjustable shock absorber and swing arm (rear)|
|Wheelbase||1,410 mm (56 in)|
|Seat height||800 mm (31.5 in)|
|Weight||192 kg (423 lb) (dry)
|Fuel capacity||16.73 l (3.68 imp gal; 4.42 US gal)|
|Related||Kawasaki S1 Mach I, Kawasaki S2 Mach II, Kawasaki H1 Mach III|
A standard, factory produced H2 was able to travel a quarter mile from a standing start in 12.0 seconds. It handled better than the Mach III that preceded it. By the standards of its time, its handling was sufficient to make it the production bike to beat on the race track. Nonetheless, its tendency to pull wheelies and a less than solid feel through high speed corners led to adjustments to the design as it evolved. More than any other model, it created Kawasaki's reputation for building what motorcycle journalist Alastair Walker called, "scarily fast, good-looking, no holds barred motorcycles", and led to a further decline in the market place of the British motorcycle industry.
The H2 was a direct result of the success of the 500 cc Kawasaki H1 Mach III introduced in 1969. The H2 engine was a 3-cylinder two-stroke with an engine displacement of 748 cc (45.6 cubic inches) which produced 74 horsepower (55 kW) at 6,800 rpm, a power-to-weight ratio of 1 hp (0.75 kW) to every 6 lb (2.7 kg) of weight. This was an entirely new engine and not a bored-out 500. Unlike the H1 500, the 750 had much more low engine speed torque, with a strong burst of power starting at 3,500 rpm to the 7,500 rpm red line.
In 1973, there were minor mechanical changes made to the carburetor jets, oil injection pump and cylinder port timing in an effort by the factory to get more MPG from the H2. The most powerful H2 was the very early 1972 models.
In 1974 the H2 engine was modified for more civilized performance at the expense of raw power. The race tail was slimmed down from the previous year. An oil-based steering damper and check valve were added. The power was reduced to 71 horsepower (53 kW) at 6,800 rpm. The oil injection system was substantially changed with two separate sets of injection lines, unlike the earlier models with one set of lines. Oil were injected into the carburettors on a separate line with a branch to each carburettor. The oil injection to the bottom end bearings (both main and rod big ends) was retained as a set of three separate lines as before. A longer swingarm improved stability. The final model had a weight of 208 kilograms (459 lb).
The 1975 model year had its steering damper repositioned.
In 1972, Kawasaki designers took a progressive leap forward in overall design appearance with the creation of the first race tail on the H2 as well as on the 350 cc S2 Mach II. The race tail covered most of the taillight assembly behind the seat and allowed for a less conspicuous rear fender. This design innovation would be copied and seen on the 1977 Yamaha RD250 and 400 and nine 1978 Suzuki models, beginning with the GS1000 down to their 250 cc bikes.
- Engine: Air-cooled, two-stroke, transverse three-cylinder,
- Engine capacity: 748 cc (45.65 cubic inches)
- Bore x Stroke: 71 x 63 mm
- Compression Ratio: 7.3:1
- Induction: 3x 30 mm Mikuni carbs
- Starting and ignition: Kick start battery and coil
- Max Power: 74 hp (55 kW) @ 6800 rpm
- Max Torque: 7.9 kg-m @ 6500 rpm
- Transmission: 5-speed, chain drive.
- Frame: Double tubular steel cradle
- Front: Suspension: Telescopic hydraulic forks
- Rear Suspension: Dual shocks, Swing arm
- Brakes: Single disc (front) Drum brake (rear)
- Dry-Weight 205 kg (423 pounds)
- Fuel Capacity: 17 liters (4.49 gallons)
- Falloon, Ian (November 2011). "Holy smoker". Motorcycle Trader (New Zealand) (211): 58–61. The magazine article says the longer swingarm was introduced with the H2B model in 1974, and the reduction in power applied to the H2C model in 1975, but these may be New Zealand-specific models.
- Walker, Alastair (2011), The Kawasaki Triples Bible: All Road Models 1968-1980, plus H1R and H2R Racers in Profile, Veloce Publishing, ISBN 9781845840754
- Weekblad Motor 1971 pages 1515 and 1516, 1760-1762