Kawasaki 500 H1 Mach III – The untamed athlete

The Land of the Rising Sun was, and still is, a rising star in the world of motorcycling. In the 1960s alone, two models emerged from Japan that turned the motorcycling world on its head: Honda’s CB 750 and the Kawasaki 500 H1 Mach III.

Whilst some might consider the Honda to have been slightly more sophisticated from a technical point of view, the Kawasaki sparked a level of enthusiasm among motorcycling and speed enthusiasts at its 1968 launch like almost no other model. 44 kW/60 hp, acceleration to 100 km/h in well under five seconds and a top speed of over 200 km/h – sensational figures for the late 1960s and this class of motorcycle. With this, Kawasaki not only eclipsed its direct competitors but also gave significantly larger machines, such as the Norton Commando 750, a run for their money.

Three cylinders, just like its siblings

Like its smaller siblings, the KH 250 and 350 S2 Mach II, the Kawasaki 500 H1 Mach III was also fitted with an air-cooled, three-cylinder, two-stroke engine with port-controlled valves. The crankshaft was supported by six bearings.

The engine had a contactless electronic ignition system and three 28 mm Mikuni carburettors. With a displacement of 498 cc and a compression ratio of 6.8:1, it delivered a maximum torque of 53 Nm (later 51 Nm) at 6,500 rpm. The maximum power of 60 hp was available at 7,500 rpm (later 50 hp at 7,000 rpm). Power was transmitted via the multi-plate wet-sump clutch to the dog-shift 5-speed gearbox, and from there via a chain on the left-hand side of the bike to the rear wheel. The Mach III’s basic chassis consisted of a double-loop steel tube frame, telescopic forks at the front, and a double-sided swingarm at the rear, with 3.25-19 tyres at the front and 4.00-18 at the rear. The bike weighed around 190 kilograms.

Where there is light, there is usually shadow too. The first-generation Kawasaki 500 H1, in particular, had a few quirks that could certainly detract from the riding experience. Firstly, there was the Mach III’s thirst. Particularly when ridden sportily at revs above 6,000 rpm, average fuel consumption was well within the range of 10 to 13 litres. This meant the distances between refuelling stops were rather short.

The independent character of the Kawasaki 500 H1 Mach III ’s chassis

On the other hand – and this was by far the greater challenge – the braking system and chassis were not quite on a par with the engine. Initially, braking at the front was provided by a 206 mm duplex drum brake, and at the rear by a 180 mm simplex drum brake. Although the word ‘deceleration’ is really a generous term in this context. Even when applied with considerable force, the machine only slowed down gradually. In 1972, Kawasaki saw reason and fitted the Mach III with front disc brakes. A significant improvement under normal conditions, they too deteriorated rapidly under heavy use.

No less dangerous was the chassis, which tended to take on a life of its own, particularly at higher speeds. The rather high centre of gravity and the rear-biased weight distribution meant that, under full load, the front wheel would lift off the ground. The telescopic fork, as well as the rear shock absorbers, were also set too stiffly; on poor road surfaces, the bike could start to bob up and down.

The Kawasaki 500 H1 Mach III was therefore really more suited to experienced riders or the particularly daring. But it was also popular with enthusiasts, who were able to significantly improve the handling of the early models by fitting Koni shock absorbers, different handlebars and better brakes.

Kawasaki itself also continuously improved the sports bike over the course of its production run. Later models no longer possess the raw untamed spirit of the early ones. By 1976, almost 120,000 units had been produced across various series. Whilst the original price in Germany was just over 4,200 DM, today they tend to fetch around 8,000 EUR. However, particularly fine examples can even break the 20,000 EUR barrier.

Photos Kawasaki Motors Europe N.V.

Author: Paolo Ollig

As editor-in-chief Paolo regularly writes about all the big and small stories related to classic cars and motorbikes. Classic dreams: Lamborghini Countach and Mercedes-Benz 300 SL. View all posts by Paolo Ollig →