Kawasaki H2 750 – Where it all started…

Kawasaki H2 750

Three then two tense

With Ian Fallon

When Kawasaki introduced the two-stroke three-cylinder 500 cc H1 in 1968, they showed that they were ready to push the boundaries of tradition in search of performance. While Honda and Yamaha are focusing on large 4-stroke engines, Kawasaki maintains their faith in 2-stroke engines.

Two-stroke engines were cheaper to produce, produced more horsepower per liter, and while they were thirsty, fuel consumption was not an issue in the late 1960s. The H1 also offered unmatched performance. yes for the dollar. When the H1 grew to 750 cc in 1971 and became the H2, for lovers of high-performance two-stroke engines, it was simply a better thing.

Often referred to as Mach IV, the H2 is an expanded version of the H1, but while the design of the three-piston port is similar, everything is more powerful. The 750’s gate timing is also lighter to produce a wider torque curve. With a compression ratio of 7:1 and three Mikuni VM30SC carburetors, the 71 x 63 mm two-stroke engine produces 74 hp at 6800 rpm.

This doesn’t sound like much for a 750 today, but in the early 1970s most 750s barely made 60hp and the closest resemblance to the H2 was the much heavier Honda CB750 at 67. horse power. While the crank and gate timings make for smoother operation, the H2 is an extremely thirsty monster that soon gained a reputation for being ‘gasoline-cooled’.

Also groundbreaking at the time was the CDI ignition system. Powered by a crankshaft-mounted generator rather than a battery, each cylinder has its own trigger, amplifier, and coil.

Although the frame and gears operate similarly to the H1, the mild steel frame has extra braces and the front brake is a single 296 mm disc with two-piston calipers. This was a much superior component to the drum brakes of the previous H1, but the H2 was still influenced by the thin fork and limp shock absorbers common on Japanese motorcycles at the time.

The weight is very moderate at 192 kg and when it comes to performance there is absolutely nothing that can match an H2 in 1972 and even 1973. In Cycle magazine’s 1973 Superbike comparison test, The H2 beat a field including Kawasaki’s Z1, Honda CB750, Ducati 750 GT, Norton Commando 750 Combat, Triumph 750 Trident and Harley-Davidson Sportster.

The H2 produces the most rear-wheel power, the most stopping force (0.922 G), the fastest lap and quarter-mile times, and is significantly cheaper. Top speed exceeds 200 km/h if you can keep the handlebars high and control the weaving.

High-speed stability is not a strong point and driving one of these early H2s at high speeds takes strength and determination. As Cycle editor Cook Neilson told me, “The H2 nearly killed me on our favorite test track in the Santa Monica mountains when I ran off the road and hit a fence.”

Despite the shortcomings, the H2 is a formidable production racer. An H2 driven by Mike Steele and Dave Burgess won the Castrol six-hour production race in 1972.

In New Zealand, the H2s driven by Alan Collison and Owen Galbraith were virtually unbeatable until 1975, especially on short stretches where the combination of moderate weight and excellent acceleration Their greatness is ideal.

The original H2A was supposed to be the final model. Unlike today, where new models offer an improvement over their predecessors, this did not happen in the early 1970s. Although the development process gradually saw changes. in terms of styling and improved handling, but these are complemented by reductions in engine performance to meet more stringent noise and emissions requirements.

By 1974, H2B was more stable (thanks to its longer swingarm), but heavier. For the 1975 H2C, power dropped to 71 hp at 6800 rpm and weight increased to 208 kg. The days when H2 was the king of performance are now over.

The H2 was not only the victim of the 1974 Middle East fuel crisis, but also the Kawasaki four-stroke Z1. Four-stroke engines were more fuel efficient and more environmentally friendly, and by 1976 they were much faster than any production two-stroke.

Now H2 is a remnant of another era. The H2 is all about engine performance, with secondary handling and convenience features like electric start noticeably absent. Despite its outstanding performance, even in 1973, the H2 was not yet a mainstream Superbike and was never as popular as the CB750 or Z1.

They are now hit machines for those who appreciate the era of two-stroke dominance. Compared to an early H2, Japanese four-stroke Superbikes are simply bland and boring…

Specifications Kawasaki H2 1972