To understand the significance of the Kawasaki Z1 900, you must first understand the impact of the original Honda CB750. When it was unleashed on the public in 1968 it had the reliability, power and technology that buyers wanted, all at a price they could afford.
Kawasaki had its own 750 cc inline four project underway, but had no desire to be also-rans to Honda’s new flagship bike. So, Kawi went back to the drawing board, determined to one-up Big Red. In 1972, they did so by releasing the Z1—the bike that arguably spawned the litrebike class that dominates the sport motorcycle scene today.
Z1 900 (1972-1976)
Although Honda’s CB750 launch had arguably been more of a milestone for the motorcycle industry as a whole, especially since it was the bike that sank the British manufacturers, the Kawasaki Z1 is the machine that gained riders’ respect in the 1970s.
Kawasaki’s delay in bringing its first proper superbike to market meant the machine grabbed attention immediately. It served notice that the Japanese industry was not content to simply rest on its laurels, as the Brits had done. It punched displacement to 900 cc, unheard-of for a sporting bike. It had double overhead camshafts, while the closest Japanese competition was still a SOHC engine. Dual disc brakes were standard in some markets, optional in others. The bike even came with an automatic chain oiler as standard! While styling is always an objective preference, the consensus was that the big Kwakka was a very attractive flagship machine.
Most importantly, its 81 horsepower stomped all over the Honda’s 68 ponies. It was 30 lbs heavier, at 510 lb compared to the CB750’s 481 lb, but riders then were no different than motorcyclists now; they were willing to put up with a bit more bulk if it meant more power.
And the Z1 was the bike to buy if you wanted to burn rubber; it was considerably more torquey than a modern inline-four, as the emphasis on those days was on street usability, not high-revving redlines.
There were other big bikes on the market, particularly from Harley-Davidson, but none were as sporty. The Z1 established itself as king, right from the start. It was fast and mean, and for a good part of the ’70s, it ruled the streets.
While the GL1000 quickly grabbed the spot as America’s favourite long-distance touring bike when it hit the market in ’75, the Z1 was also a very popular bike for laying down big mileage as well, and the marketing copy of the time made much ballyhoo about the machine’s long-distance capability. In those days, you had to deal with aftermarket parts if you wanted to properly set up a bike for touring, and if a Z1 owner bolted on a Vetter Windjammer, he/she was ready to go.
Although today the Z1 is rightly reckoned a poor-handling machine (squirrelly suspension, iffy brakes, too much weight), it still had high-profile race wins in its day as well. Canadian rider Yvon Duhamel piloted one successfully in the US in the 1970s (he even set a new lap record at Daytona aboard the bike, and it held the AMA and FIM 24-hour endurance racing record at one point). They were also flogged at the drag strips, although they’d be supplanted by Suzuki’s GS lineup very quickly once those big four-cylinders hit the market. Of course, the Z1s are commonly seen now in the vintage racing scene, but many of those machines have been upgraded from their evil-weevil handling days of yore.
The KZ900 was a refinement of the Z1, not an all-new model; it came along as Kawasaki introduced the broadened KZ lineup of four-strokes, which included such machines as the stalwart commuter-oriented KZ400, the middleweight all-rounder KZ650, and many other models, culminating in the mighty six-cylinder KZ1300.
At this point, though, the KZ900 still ruled the roost. As you can see from the video above, the standard model wasn’t that different from previous editions (the carburetors were changed to meet new emissions standards, a trend that we still see), but Kawasaki had a trick up its sleeve.
To shake things up, Kawasaki introduced a custom-style cruiser based on the KZ900, calling it the KZ900 LTD. Although it didn’t have the butt-dragging lines that would typify made-in-Japan cruisers of the low rider generation, it’s fair to say this was the first made-in-Japan cruiser, and frankly, it doesn’t get enough credit for that today.
The KZ900 LTD had pullback bars, not buckhorns, but there was a funky megaphone muffler, standard dual disc brakes up front, chrome, a stepped seat, white-letter tires, 16-inch rear wheel, and chrome geegaws. Aside from the inline-four engine, the combined drag bike/custom cruiser result wouldn’t look that out-of-place in a certain made-in-America manufacturer’s lineup today. For that matter, Kawasaki could actually claim this bike was made in America, as it was assembled in a factory in Lincoln, Nebraska; today, many riders forget Kawi’s US factory presence, but it’s probably no coincidence that some of its most popular models were built, at least partially, right here in North America.
What’s that you say—there’s no way the KZ1000 was in production until 2005? It sure was, but we’ll get into that later.
First, let’s look at what Kawi brought to the table with the KZ1000. It wasn’t just a mere displacement bump. Today’s inline fours are silky-smooth, but the first-gen I4s from Japan weren’t as free from vibration, and the KZ1000 got a new crankshaft to keep the shaking to a minimum. Some models also came with an oil cooler as stock. The frame was also supposedly made of thicker tubing, to stiffen it up. The 1980 KZ1000 Classic even came with fuel injection, and the Z1R-TC was the first turbocharged Japanese motorcycle to hit the North American market (although it was technically modified by an aftermarket company, these were available through dealers—much more on that fascinating bike here).
Overall, the machine was a look at the future. It was arguably the first superbike in the litre class. Kawasaki had learned enough about chassis design that the big Z was a better-handling machine than its predecessor, and the KZ1000 was campaigned succesfully in production-based racing around the world, especially in the AMA, where a succession of high-profile riders took championships aboard the machine.
The most prominent was probably Eddie Lawson; his high-speed heroics managed to inspire the ZRX1200 tribute model years later. Here in Canada, it was the weapon of choice for several frontrunners, including Lang Hindle, Rueben McMurter, George Morin and Frank Mrazek.
Along with the sportier standard model, there was a hot-rodded KZ1000R in 1982 and 1983, the original Eddie Lawson Replica, with go-fast parts added off the GPZ900. There was an LTD version of the KZ1000 as well, with cruiser styling; other mutations included a shaft-drive version for touring (Windjammer, hard luggage, and other touring accessories were available as an option). Some markets (not all!) got a weird hybrid of a KZ1000 shaft drive chassis with a GPZ1100 motor, called the the KZ1100. And then there was the long-lasting KZ1000P, a police bike built around the big inline-four platform.
Most versions of the KZ1000 were discontinued in 1984, when the GPZ900R, the original Ninja, hit the scene, but the KZ1000P proved to be the longest-lasting of not only the KZ1000 series out of all the big classic inline-four UJMs from any of the manufacturers, staying in production in the Lincoln, Nebraska plant until 2005. Maybe its popularity was due to its starring role in a certain ’70s television cop show?
It wasn’t just racers and the law enforcement good guys who rode KZ1000s back in the day, though; they also had a very prominent role in Aussie B-movie classic Mad Max, where a pack of Kawis donated by the distributor were flogged righteously throughout the film by the Toecutter and his gang of bikie thugs, as you can see in the doc below.
Where do we go from here?
We’ve already said the classic Japanese inline-four is due for a comeback. Will the Z900 RS be the bike that pushes the trend into high gear? If it can capture the blend of performance and style that the original Z1 900 and KZ1000 did, we’d guess it will be very successful. Maybe it’ll even start driving prices of these old Zeds up again, if interest builds. We’d all be better off in a world with less UJMs being hacked into ill-handling bobbers and bodged-together cafe racers; if you’ve got one of these old Kawis in your shed, maybe you should hang on to it now, just in case the value climbs?