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Kawasaki GPz 500S / EX 500R Ninja

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Make Model

Kawasaki GPz 500S / EX 500R Ninja

Year

1989 - 90

Engine

Four stroke, parallel twin cylinders. DOHC, 4 valves per cylinder.

Capacity

498 cc / 30.4 cu-in
Bore x Stroke 74 x 58 mm
Cooling System Liquid cooled,
Compression Ratio 10.8:1
Lubrication Wet sump
Engine Oil Semi-Synthetic, 10W/40

Induction

2x Keihin CVK34 carburetor

Ignition 

TCI (Transistor Controlled Ignition)
Spark Plug NGK, DR9EA
Starting Electric

Max Power

60 hp / 43.7 kW @ 9800 rpm 

Max Power Rear Tyre

54.7 hp @ 9500 rpm

Max Torque

46.1 Nm / 4.7 kg-m @ 8500 rpm
Clutch Wet, multiple discs, cable operated

Transmission 

6 Speed 
Final Drive Chain
Frame Iron, Double cradle frame

Front Suspension

38mm Telescopic forks
Front Wheel Travel 130 mm / 5.1 in

Rear Suspension

Swinging arm, single shock adjustable for spring preload
Rear Wheel Travel 100 mm / 3.9 in

Front Brakes

Single  270mm disc 2 piston caliper

Rear Brakes

160mm drum

Front Tyre

100/90-16

Rear Tyre

120/90-16
Rake 63°
Trail 91 mm / 3.5 in
Dimensions Length 2110 mm / 83 in
Width     685 mm /
27.0 in
Height: 1160 mm / 45.6 in
Wheelbase 1435 mm / 56.5 in
Seat Height 770 mm / 30.0 in

Dry Weight

170 kg / 370 lbs
Wet Weight 200 kg / 441 lbs

Fuel Capacity 

15.9 Litres / 4.2 US gal

Consumption Average

18.2 km/lit

Braking 60 - 0 / 100 - 0

14.6 m / 39.9 n

Standing ¼ Mile  

12.5 sec / 164.8 km/h

Top Speed

197.9 km/h / 122.9 mph

Kawasaki may want us to think of their new 560 as half an RX but they are selling themselves short. What they should be saying is that they can make twins to match the performance of four-cylinder motors and remind us of the impressive 250 Scorpion and the 305 version that transformed it.

The ZX500 is another step along that particular road but it isn't as dramatic as the image created by the 1000RX and its 900 predecessor. And the new twin is four-valved and water-cooled, so I suppose they can justify all the claims. But when you cut through the hype, it's still a twin. And w hen you cut through the timing lights, it's nearly as quick as the fours.

It causes a bit of an identity crisis — and one which doesn't stop at performance. Why build a twin, one might ask? Because it is smaller, cheaper and simpler than a four, another might reply. Wrong. It doesn't quite beat the fours; nearly-as-good-as, considering-it's-a-twin is a better description. And it isn't cheaper. Another problem is that the sports 550s have grown into 600s with 140mph performance. Another problem is that Kawasaki recognise the value in their other bikes and the shaft-drive 550 is just £2,399 which is not so easy to reconcile with £2599

I for the twin. Or maybe we're not supposed to compare them, just take them on their own | value.

If that's the case, there's a lot about the twin which is great. And some which is harder to digest. Let's get the bad bits over first. From appearances, it is made cheaply. Without a lot of loving care it could look really scrappy after six months. That has to be speculative because we only had the bike for two weeks. It  particularly the wheels and forks — stood up well to the last of the winter salt.

But it was already getting a bit rattly, there was a certain roughness in the engine and the bike snatched suddenly between drive and overrun, as if a chain was loose or a cush drive had gotten squashed.

It had deteriorated quite quickly from its sweet, smooth state when we first picked it up, and it had done less miles than most of our road test models. It also developed two faults, almost simultaneously, which caused a certain amount of confusion. One ignition coil failed, over a period of two or three miles, rather than suddenly. The fuel tank breather, which runs behind the tank and under the seat, also got trapped, which was probably our fault for disturbing it and not re-routing it correctly.

The result was that the breather caused an air lock, which caused fuel starvation which caused an intermittent misfire under load and occasionally cut out one cylinder. The faulty coil achieved the same thing but fortunately it happened when the bike was on its way to be dy no-tested.

The dyno is a good place for diagnosing faults — but by the time the faulty coil had been found, the tank had been removed and the trapped breather no longer existed! We only noticed it later when the bike had been stopped after a run and the air rushing through the restricted breather was making a high-pitched whistle.

The only other fault with the 500 is its identity crisis. When people ask why Kawasaki have built such a bike, the answer is not immediately obvious. It is more expensive than the sensible 550s, it is slower than the sporty middleweights; so who is it aimed at?

Maybe you are in a better position to answer that question than we are. The bike itself has got a lot of attractive points; from a ride and handling point of view, it has a lot in common with the Honda VF500. It feels like an overpowered 250, light and small, with an engine that buzzes on and on.

The 500 comes in with a bit of a surge at 7000; above that it feels smooth, like a four. Below that speed, the motor has the chunky, lop-sided, burbling nature of a 180-degree twin. Which is what it is, plus a balance shaft and rubber engine mounts.

To get at the performance, you need to work away at the six-speed gearbox and, if you like this style of riding, the 500 is at its best on country A roads or good B roads. The transmission roughness spoilt it on slower roads and sometimes made the gearshift a bit clunky.

Under motorway conditions it would cruise happily at 80 although it was sometimes closer to flat out than the rider realised . . . however, everybody agreed that the performance was impressive for a twin.

And here we have a division. Forgetting price and comparisons with 550-fours, I liked the twin, I enjoyed its rapid handling and the buzzy motor. Rupert found it unsatisfying and wanted more midrange, even at the expense of top end power, which he admitted was impressive. On top of that he didn't like the handling; it wasn't as easy to get used to as, say, an RD350 — which seems to be its nearest competitor in terms of street performance. Finally, he said, the whole bike didn't make any sense — and we're back to the price and performance comparisons again.

The problem seems to be the price, which puts it into the four cylinder bracket — you could even get a newish 750. It will outperform the likes of the SRX and VT, but then it costs a lot more.

In some ways the Kawasaki is a bit basic, with touches of the economy class roadster, in others it borders on the exotic. It is light  at 3711b it is in the same bracket as most 400s and feels even lighter, helped by the 16-inch, three-spoke wheels which give sharp steering even on conventional amounts of rake and trail.

It is the sort of bike which demands concentration; it isn't unstable, like some racers, but it isn't stable either, in the sense that you can't sit back and relax, keeping it on course with lazy steering corrections. You need to keep on top of it all the time, otherwise it will wander all over the place.

The engine demands a similar level of attention-. You need to use the gears as much as on a lightweight for rapid overtaking, although the acceleration through the gears can be exhilarating when the motor hits the top end of its power band.

While the steering is fast and precise, one problem with light bikes and with 16-inch wheels, is that the feedback to the rider is reduced. The harder you push it, the less feel there is, giving the impression that it is all about to break loose in the biggest possible way. Perhaps it is a good way to keep people well on the safe side of the ragged edge.

In long fast corners the bike would develop a slight weave; it was at its best in mid-speed turns, snapping in and out of large roundabouts with a rate of turn which would do credit to a YPVS.

Braking was powerful, the single disc needing heavier than average pressure which somehow suited the nature of the bike. The dual piston caliper has a smaller leading piston which, according to Kawasaki, gives more even wear and thus more uniform pressure and better performance. There was no doubting the performance, whether it was on full and pinning the bike down, or feeding it in gently as the bike rolled over into a tight corner.

The rear brake is a drum, and that's all I can remember about it.

Being able to use performance depends very much on the hike's ridmg position and the 500, although comfortable, could have been stretched out a little more. The handlebars were a shade too high, the footrests an inch or so too far forward. The layout and controls were, as always, just right.

An example is the old-style fuel tap, which has two horizontal positions, one off and the other for reserve. I hadn't checked to see which was which, so the first time the tank went on to reserve, I didn't know which way to turn the tap, and twins stop pretty quickly when the fuel runs dry. The tap was easy to twist one way, and more awkWard to move in the opposite direction; I assumed that, if the designers had done their job down to the last details, then reserve should be in the easy direction. It was. Funny how the Japanese can be so predictable in these things.

The tank  at 4 gallons  gave a respectable range even when the 500 was down to 43mpg in its headbanger mode. Most of the time it ran around the 48mpg mark, and could be persuaded up into the mid-50s without sacrificing too much performance. Then you could look forward to 190-mile ranges and still have reserve in reserve.

Take the bike on its own and it has a lot of good points; few real faults but it has characteristics which you either like or hate. After riding a 125 it would feel great, but if you happen to like the lazy way that BMWs perform, the 500 would be less than impressive.

Compare it with other bikes and you hit its biggest problem: what do you compare it with? It looks like Kawasaki have tuned it for enough top-end to compete just  with the 550s. And they've priced it higher than both of their own 550s ... so would you rather pay a bit more and get the 600?