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Kawasaki GPz 500S
(EX 500R Ninja)

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Make Model |
Kawasaki GPz 500S EX
500R Ninja |
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Year |
1987 |
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Engine |
Liquid cooled, four stroke, parallel twin cylinders.
DOHC, 4 valves per cylinder. |
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Capacity |
498 |
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Bore x Stroke |
74 x 58 mm |
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Compression Ratio |
10.8:1 |
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Induction |
2x Keihin CVK34 |
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Ignition /
Starting |
Electronic / electric |
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Max Power |
60 hp 43.7 kW @ 9800 rpm (rear tyre 54.7 hp @
9500 rpm ) |
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Max Torque |
46 Nm @ 8500 rpm |
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Transmission /
Drive |
6 Speed / chain |
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Front Suspension |
38mm Telescopic forks |
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Rear Suspension |
Swinging arm, single shock
adjustable for spring preload |
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Front Brakes |
Single 270mm disc 2 piston caliper |
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Rear Brakes |
160mm drum |
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Front Tyre |
100/90-16 |
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Rear Tyre |
120/90-16 |
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Dry-Weight |
176 kg |
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Fuel Capacity |
16 Litres |
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Consumption average |
18.2 km/lit |
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Braking 60 - 0 / 100 - 0 |
14.6 m / 39.9 n |
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Standing
Mile |
12.5 sec / 164.8 km/h |
|
Top Speed |
197.9 km/h |
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?
Source PERFORMANCE BIKE 1987
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