Kawasaki Z1: PH2 Heroes

With the Honda CB750 to beat, Kawasaki's Z1 needed to be fast, refined and cool. It was all of that and more...

In 1968, Steve McQueen drove a Sherwood Green Mustang GT Fastback into motoring legend. Fifty years later, Ford's official homage to that car - the Mustang Bullitt - has sold out. And we don't mean in a bad way.

In 1973, Kawasaki rewrote superbike history with the Z1. Forty-five years later, the Z900RS - Kawasaki's official homage to the Z1 - has been described by more than one impartial scribbler as the best retro bike ever.

Both feats are impressive, given the passage of time between original and tribute. You could say that Kawasaki's effort is even more impressive than Ford's, given that everything is 'on show' on a naked motorcycle. The essential RS engine plus chassis package is, more than conceptually, the same now as it was in 1973 - or 1967 if you go right back to the 'New York Steak' codenamed project bikes that preceded the dumbfounding arrival of the Z1.

You also have to add in the style-cramping fact that the 1973 Z1 that Kawasaki is hommaging now was - and still is - a hell of a tool. It was meant to be a 750, but Honda kiboshed that plan by unveiling its own world-dominating (they hoped) CB750 at the 1968 Tokyo Show.

Kawasaki therefore had to come up with something that would not only blow Honda into the weeds but also start them on their own self-proclaimed quest to become the motorcycle brand for power and speed. The Z1 would have to displace the ageing Vincent HRD that, even in the late 1960s, was still regarded as the ultimate sports machine.

The Z1 went on sale in the UK a year before Kawasaki had established any sort of administrative base here, let alone any dealer network. The first bikes were brought in by importers Agrati. In 1974, Kawasaki UK still only had 15 road bike dealerships selling a total of 1200 or so bikes from a six-model range. But what bikes they were.

Kawasaki had three trump cards giving them a flying start in the UK. For a start, they came into the big four-stroke market with major street cred thanks to the eyeball-popping reputation established by their scarily quick two-stroke triples, the H1 500 and the H2 750.

Secondly, there wasn't much non-Kawasaki opposition. The only other bike in the Z1's 130mph+ class was the considerably more expensive (and challenging) Laverda Jota. BMW's iconic 'gentleman's express', the R100RS, only produced 70hp from its old-school flat-twin motor and was still three years away.

Thirdly, despite their pioneering and deeply impressive CB750, Honda wasn't much liked here as a brand. Not only were they seen as a 'white goods' outfit, their annoyingly reliable bikes took a lot of the blame for killing off the British motorcycle industry. Hondas went like a watch, but they were perceived as being about as interesting as a Timex.

Honda's CB750 actually helped Kawasaki as it allowed Ben Inamura and his team to do remote market research on someone else's creation and then use that to improve their own beast. In the Z1's case, the main improvements were to double the Honda's cam count and take the capacity out to a then-outrageous 903cc.

Early Z1s produced a ridiculous 95hp in prototype form, but problems with the pistons and the oil breather meant that it wasn't a reliable figure. Kawasaki dressed some prototypes up as Honda 750s and sent them out onto American roads for shakedown testing. 82hp was chosen as the final production ouput, but even at that reduced figure, the prototype Z1s were chewing through final drive chains at a fearsome rate, despite the automatic chain oilers that were fitted to pre-Z1B models. Kawa's big strokers had had similar problems, which were eventually solved for all powerful bikes by the advent of O-ring chains.

It's difficult to overstate the impact of the finished Z1 when it officially hit the streets. In terms of shock and awe it was on the same level as the Lamborghini Countach. For many a likely lad in the 1970s it was the only bike to have.

In 1973, Triumph released its 2.0 Dolomite Sprint. That was a sporty sort of motor much loved by the motoring press. With 127hp, it had a power to weight ratio of 8kg per bhp. The 82hp Z1's figure was 2.8kg per bhp. Do the math to get an inkling as to the quantum leap this bonkers Kawasaki represented.

The first-year Candy Brown bike you're looking at here has been in Patrick Bullimore's garage for the last 40 years. He bought it for £500 in 1978 from the original owner, having helped that same chap to buy it new in August 1973 by giving him a lift to Read Titan, the original vendors. "I did own a Z1 in 1974, and always regretted selling it," recalls Bullimore, who started to restore this bike in 2001. The engine was rebuilt in Manchester by a well-known Z1 specialist and all the cycle parts were restored under the watchful eye of Z1 guru Dave Marsden. The bodywork was repainted by Dream Machine and a 1976 Z900 exhaust system was fitted, as they were the only original pipes you could get from Kawasaki in those days. Now, if you need a new Z1 system, it's aftermarket non-original, or bespoke if you can find someone daft enough to take the job on.

The Z1 is no lightweight at around 230kg - the new Z900RS weighs 215kg - but once you're moving you'd never guess it. Peak power doesn't arrive until 8500rpm, which is high for a two-valve head. Fortunately, changing up early doesn't leave a 2018 rider feeling short-changed. Progress is smooth and relentless. The engine is still as wonderful and characterful today as it ever was.

Early road testers were gobsmacked not just by the Z1's performance but by the effortless refinement with which it was delivered. Extensive use of rubber mountings made it smoother even than the CB750, and that was hardly rough. Motor Cycle News's man Brian 'Badger' Crichton was the first British journo to ride a Z1 in the UK. He described the "non-stop crescendo of power... when I looked down at the speedo and saw over 130mph I just couldn't believe it." Badger was a little bloke, so even allowing for the 6% optimism of the speedo it must have been quite a culture shock for him.

Japanese riders must have been annoyed by their country's 750cc capacity limit and the 42mph motorway speed limit that was in force at the time, both of which meant the Z1 was off limits to them. Kawasaki did do a home market 69hp Z2, but it was a poor subsitute for the full-fat Z1.

Suspension is one of the areas in which big advances have been made over the last half-century, but even with the limitations of 5-way rear shocks and spindly front forks you're still likely to be taken aback by the balance of a well set-up Z1. The high buckhorn bars and simple but supportive seat provide a fine riding position for old British scribblers with original backs, and the end result is a surprisingly excellent town bike for anyone over 5ft 8in tall.

Which poor old Brian wasn't. That must have made what happened at the end of the 130mph straight all the more knee-trembling. "The machine suddenly broke into a high-speed wobble... I just sat there for what seemed forever, waiting to be thrown off. Thankfully the machine eventually came back under control."

There's something really evocative about the typefaces Kawasaki used for both clock digits and badgework. With only a single front disc (that was notoriously ineffective in the wet) and a drum at the back, you tended to spend a lot of time concentrating on the clock numbers. Luckily, Z1 instrument design is a paragon of simplicity and clarity that still hasn't been bettered.

Cycle Guide's amusingly named road tester Bob Braverman rated the stability of the bike on the special track at which he and other US hacks were invited to test the Z1. For some reason, ahem, this track didn't have any corners on it, but Bob was impressed by the fact that he could "cruise at 120mph sitting bolt upright in the saddle... there are very few motorcycles we have ridden that can come close to achieving this. The rider is not required to hang on with a vice-like grip in order to keep the front end pointed in the direction he wishes to go. It is merely necessary tp lightly rest his hands on the grips, and we found the bike will track perfectly every time." Eeeh, straight from the days when men were men and women were grateful.

Aboard Pat's bike on the somewhat bendier and bumpier roads of Surrey, the motor felt a little 'woofly' as if it wasn't getting quite the right mix of air and fuel. That's not exactly uncommon on old Japanese bikes with original carbs. Even so, the 66x66mm Z1 motor was smooth and super-tractable from low rpm, the controls light and the steering responsive. It's a lovely ride and perfectly useable on modern-day roads.

In 1973 it was a revelation. Cycle magazine put the big questions about whether or not Kawasaki had indeed created the King Motorcycle they were claiming to have built. "Would you believe a machine that can idle along in town with no fuss?" they asked. "And tour effortlessly at any old speed? And streak down country roads? And break the back of any other motorcycle at the strip or speedway? You can believe it now. A velvet blunderbuss, and every inch a King."

Is a Z1 a practical proposition in 2018? Many parts are now either n/a or hideously expensive, but there's a healthy aftermarket of love and craftsmanship to help you realise your Z1 dream. Dave Ennis of Buzzworkz has as much Z1 experience and expertise as anyone. He does brilliant work improving Z1s both mechanically, electrically and chassis-ily, giving the frame the sort of bracing it should have had from the start, all without altering the classic original look if that's something you'd like to retain. If you're not that bothered about originality he'll hold your hand and take you down the Ohlins/Sanctuary route, or to any point in between standard and full restomod.

You'll always be safe in the knowledge that your investment is totally secure, because the Z1 has never been anything less than a legend, and the supply of bikes is extremely limited. "It's thought that only 30 odd bikes were brought in to the UK in 1973, and that there are now only a handful left," says Patrick.

A quick footnote. Back in 1989, a chap called Steve Webster won a restored Z1 in a magazine competition. The magazine was SuperBike. I worked there when I was young, foolish and a lot more bouncy than I am now. Stupidly, the mag waited until I'd gone before they organised that competition. If I'd hung on a bit longer there might well have been an unexplained fire in the Comp Entries box. Ah yes, great times.

Values, needless to say, can only go one way. In 1989, Steve reckoned his Candy Yellow Green prize bike was worth maybe £4000. Today, if you did manage to track down a really good example like Pat's, you'd probably have to start the bidding at £18,000 - and you could easily end up looking at a figure considerably larger than that.

You won't be getting Pat's Z1, though. "I will never sell this bike," he says flatly. "My wife would never forgive me. it is her favourite bike of all time."

SPECIFICATIONS - KAWASAKI Z1

Engine: 903cc DOHC 8-valve transverse four, air-cooled
Induction: 4 x 28mm Mikuni carbs
Power: 82hp at 8500rpm
Transmission: 5-speed, chain drive
Weight: 230kg
Top speed: 133mph @ 8500rpm in top
Frame: Steel duplex cradle
Seat: height 32.5in
Wheels: 18in
Braking: 11.7in single disc front, 8in drum rear
Price new: £1177 inc tax
Value now: £18,000-£30,000

We thank Pat Bullimore for trusting us with his superb Z1, and Pat thanks Dave Marsden of Z Power for parts and knowledge and Stephen Smethurst for the engine rebuild.

Photography credit: John Goodman.