Kawasaki H1 500 Mach III


Make Model

Kawasaki H1 500 Mach III


1974 -75


Two stroke, transverse three cylinder, piston valve


498 cc / 30.4 cu-in
Bore x Stroke 60 х 58.8 mm
Cooling System Air cooled
Compression Ratio 6.8:1
Lubrication Injectolube, automatic pressurized injection


3x Mikuni VM28SC carburetors


Starting Kick

Max Power

60 hp / 45 kW @ 7500 rpm

Max Torque

56 Nm / 42.3 lb-ft @ 7000 rpm
Clutch Wet multi-disc


5 Speed 
Final Drive Chain
Frame Double tubular steel cradle

Front Suspension

Telescopic hydraulic forks

Rear Suspension

Dual shocks, swing arm

Front Brakes

Single 296mm disc

Rear Brakes

180mm Drum

Front Tyre


Rear Tyre

Wheelbase 1400 mm / 55 in

Dry Weight

174 kg / 384 lbs
Wet Weight 188 kg / 414 lbs

Fuel Capacity 

15 Litres / 4.0 US gal
Standing ¼ Mile   12.4 sec

Top Speed

200 km/h / 124 mph

Road Test

Kawasaki HI vs Triumph X-75 Bike magazine 1974

Kawasaki's early 1970s sportsbike range was dominated by light, powerful two-stroke triples: from the 250cc SI through to the fearsome H2 750cc, the KH500 being a suitable midway point.

Developed from the earlier HI, the original triple of 1969, the KH500 had a piston-ported two-stroke engine in a steel-tube cradle frame. Conventional if rather insubstantial suspension and braking components were marginal on the earlier HI, but improved in later models. Later models also tended to gain weight over the originals, and the engines were re-tuned for less ferocious power. By the late 1970s, the poor fuel consumption, reliability and handling of the triples made them less popular, and they were replaced by newer four-stroke designs.


I rode a 500 Kawasaki I found it hard to believe that even the notoriously gullible motorcycling public could be taken that much for granted. The bike was an early H1B version of the Mach III, and the fast and rough sweeps that lead south from Davicks' through Pie City (Mel ton Mowbray) and the Welland Valley couldn't have served better for exposing its raw failings. The thing pitched and yawed ail over the road, and the motor was so pipey that at 70 mph in top you had to change down before it could manage to accelerate the bike.

Even the cynically laid back minds of journalists can occasionally be stirred to emotions of incredulity: here it was happening to me. There was only one way to describe the Kawa thanatoid. a chill and sinister word that the dictionary will tell you means "resembling death, poisonous deadly." A bit melodramatic? Well, anyone who'd tried to hustle that particular piece of two-wheeled demonry along that same tar mac switchback wouldn't have disagreed that much.

On that occasion, somebody else got lumbered with what then seemed the hazard prone task of testing the Mach III. so my experience of the breed was limited to those few fetch-and-deliver miles. But it seemed I wasn't alone in sharing feelings of some outrage at the bike, because around that time this very mag headlined it as "The Fastest Camel in the World.'

Even those publications most fearful of the advertiser's £ found they had to criticise the Mach III. and eventually even hell-bike builders Kawasaki had to take notice, for they later brought out modified versions that were alleged to handle better and to have had the razor edge taken off the power band, without actually losing any top end performance.

By this time the bike had reached model designation Hlb and Davicks wanted us to try the thing again, so why not give it a chance? Accordingly we did. and sure enough the first point to be noted was a much improved riding position. The controls "fell readily to hand", to use a piece of hackneyed journalese much beloved of a certain weekly publication: the phrase does not mean that the "bars are endowed with qualities magnetic to human flesh, merely that their spread is about shoulder width, and they have a flattish profile. Thus they're good for town trundles or fast highway work. Kawasaki have also refrained from falling into the well trodden Jap trap of placing the footrests too far forward, and all this, combined with a plushly padded seat, means that the sacrificial rider of an II IE at least feels he has a half decent chance of retaining control, even if he does suspect that it'll handle like a paranoid serpent on greased ice.

When collected, the bike had only a couple of hundred miles on the clock, and despite Mike Volans' confident call the "buzz it to six", it seemed prudent to keep to around 60 mph for a while yet. during which time it became apparent that the motor had indeed been softened up. It'll rustle 'round on a whiff of throttle (damn. I really must find something else to read on Wednesday mornings) at three to four grand in very gentle style, and what's more not one of the three spare plugs in the rack beneath the seat was needed during over a thousand miles of operation that changed gradually from light listed ambling to hard charging as the motor bedded in. Yup. it's fair to say that the Vlach III does OK as a lownie. with certain reservations.

First off. it's a very noisy machine, and unless you hold fast to a policy of deliberate urban pussyfooting, heads will turn and folk will stare. It's not just the raspy edge to the exhaust note, but more the jingle-jangle resonance from the cylinders that would have made the Mach III ideal transport for the original Tambourine Man. Then you've got the business of having to slip the clutch to keep revs from dying if you want to make a rapid streak from the lights: all in all. the Mach III rider sometimes feels an undue degree of attention bearing his way.

The somnolent ritual of the running-in process spreads a calm over everything you do with a bike: if you can't lam along the straightaways at hotshoe speeds, you lend not to corner very hard either. So there was not too much to note about the Kawa's handling at first, except that despite a surpris ingly high weight of 448 lbs., the bike was light to pilch around.

Now let's jump a few hundred miles to the point where the engine was almost run in. and the Kawa was wobbling fast enough for its qualities as a high performance sports machine to be appreciated, or otherwise. We'll start by saying that Much III motorcycling remains by no means everyone's two-wheel dream set down in real life alloy, steel, rubber and plastic. There's a sizeable group of naive people, you see. thai actually thinks motorcycles should lake corners in predictable and stable manner. Let's, therefore, hope that the idealist souls of this market segment are not swayed by the admittedly finely styled lines of the Mach III. Once they've bought it. they really won't like it.

However, if you're of a cast of mind that allows you to admire an object as much for its quirky faults as for its qualities, read on. For although the 500 Kawasaki plainly just don't handle, it could be that you'll get highly excited indeed about an aura of fully committed total energy that hangs over the whole plot. For one thing, this is the world's fastest 500 cc production motorcycle, as is proved in no uncertain fashion by its dramatic speed trap figure of one-one-zero mph (yes. we know a good Goldie is supposed to do likewise, but a rider of that classic Big Single would still be slipping his clutch in bottom gear when the Mach III man would have accelerated into the next county. This is merely a fact, not an argument in favour of one or other of the motorcycling styles represented by these two very different bikes of similar capacity. Maybe we'll explore that in a future issue).

Not only does the Mach III have very great high speed potential, that amazing three-cylinder motor is more than willing for it to be used. The HIE will accelerate from 70 (5.000 rpm) in lop. and at 90. a fair old cruising speed for any bike, the engine gives out a low moan of satisfaction that only tells you it's happy to accept more throttle yet. The real power still lies above six grand, but at last they've filed away that vicious step that was a very real hazard in riding an early Mach III if you happened to do something very unsmart like hilling ii while accelerating out of a second gear bend.

Still on the thrillsville engine qualities, when you have to slow from high speed for a tight bend, you can picture yourself as ihe fearless 'von Du Hamel himself backshift-ing his works Green Meanie from a ton-seventy on the Daytona front straight for the bottom gear turn thai leads to ihe infield.

But doubtless by now you want to know-all the gory facts of ihe weirdo handling in every detail, and rightly so. In the first place, there are several very important things that you jusi DON'T DO when corn ering on a 500 Kawasaki. Perhaps most important, you DO NOT shut off and brake when committed (o a fast line in the middle of a bend. If you do. the machine will break into frenzied leaps and bounds in a way that can take you perilously close to the verge or central white line, while placing the rider in a rapidly mounting state of panic and terror.

Secondly. DO NOT take liberties on unfamiliar bumpy roads. Mach 111 handling is at its weakest on rough tarmac, although matters are not loo bad if you know where the real crisis bits are and can moderate speed or angle of lean accordingly. If you tramp on regardless on unknown backWays of uncertain surface quality, you're asking to be caught out sooner or later.

Also. DO NOT swoop over crests of hills when banked over. I unwittingly did this on one occasion, and was later informed by a pursuer that the ensuing gyrations would have gone down a treat if performed as the weave - through - the - cones bit of the RAC-ACU training scheme.

Like the 750 H2. the Mach III is provided with an hydraulic steering damper adjustable to a number of positions. But fiddling about with this and with different rear suspension settings made hardly any noticeable difference to the bike's ramblings. except that twisting the rear units to their hardest position did delay the onset of the wobbles somewhat.

To be fair, the HIE does not handle as badly as I remember the H1B did. but it's still a pretty vicious creation. Surely then, the marvels of its speed-lusting engine can't overshadow the bike's handling problems so much that it becomes a great machine? But that's just what docs happen, or something like it anyway, because there's no doubt that the Mach III is a very' exciting motorcycle to ride, and not at all the disgusting heap that you'd expect it to be from reading a description of its handling qualities.

It took me a while to figure out exactly why (not everyone has the nimble mind of a VVedgie Benn). but here's how the theory goes: to ride a Mach HI fast, especially on any kind of sub-standard road surface, demands total concentration and effort of a kind not needed on more predictable machines. But if you do it well you get a lot of satisfaction, because not only are you getting the familiar blurred scenery sensations of rapid riding, but you're achieving it on a machine that's difficult to master under those circumstances. The net result, therefore, is More Thrills Per Mile.

This latter benefit, however, only goes part way to offsetting the Notoriously Few Miles Per Gallon one gets when wing dinging on Kawasaki triples. The Mach III is about as thirsty as the 750. giving a figure in t the low twenties under hard riding.

Even during the running-in spell we never gol more than 30 mpg. Equally infamous is (he minute size of Kawasaki triple fuel tanks, in relation to their prodigious thirst for the stuff. On the Mach III. fuel stops every 60 to 70 miles are the order of the ride.

Other Mach III mutterings: the front brake requires a lot of pressure, but other wise stopping powers of the single front disc/rear drum set up are good: there is no vibration, due in part to the rubber engine mounts on the new model: the gearbox has a light and close action, although having neutral at the bottom doesn't appeal because you can get confused and tread through to it when you really wanted bottom gear; the Japanese Dunlops. particul arly that squat 4.00 section rear cover, feel reassuring in the dry. though the kindly English summer meant we couldn't test them in the wet (sighs of relief): and finally, it really is a good looking motorcycle.

Back in the August issue, you may recall, we waxed very lyrical over the 400 cc S3 triple, which is almost as fast as the 500. has none of the latter's handling hangups, and. it transpires, is £162 cheaper at a very reasonable £549.

So is there any room for the 500? Well, there are people who prefer to live at the outer limits all of the time. These are the hardy souls who could be tempted into Mach III ownership, always providing they could afford the fuel bills. The difference between riding a Vlach III and. shall we say. more sensible motorcycles such as the 500 Su/uki twin or the 500 Honda, is the differ ence between . . . well, if you can't think of one or two very sensuous comparisons there's no point in you exploring further than the practical ironware. •

Source Bike Magazine 1974