Four
stroke, transverse four cylinder, DOHC, 4 valves per cylinder.
Capacity
746 cc / 45.6 cu-in
Bore x Stroke
70.0 x 48.6 mm
Cooling System
Liquid cooled
Compression Ratio
10.5:1
Lubrication
Wet sump
Induction
4x 34mm Mikuni carburetors
Ignition
Transistorised, electronic advance
Starting
Electric
Max Power
92 hp / 67.2 kW @ 10000 rpm
Max Torque
7.2 kg-m / 52 lb-ft @ 8500 rpm
Transmission
6 Speed
Final Drive
Chain
Front Suspension
Air assisted forks, 160mm
wheel travel.
Rear Suspension
Single shock swinging arm,
109mm wheel travel.
Front Brakes
2x 270mm discs
Rear Brakes
Single 256mm disc
Front Tyre
120/80-16
Rear Tyre
130/80-18
Wheelbase
1495 mm / 58.8 in
Seat Heigth
780 mm / 30.7 in
Dry Weight
228 kg / 502.5 lbs
Fuel Capacity
22 Litres / 5.8 US gal
Consumption Average
36 mpg
Standing
¼ Mile
12.4 sec / 106 mph
Top Speed
218.8 km/h / 136 mph
.
GSX750 VS GPZ 750
I was one of the few who didn't manage to cock a
leg over one of the new generation of 750s we featured in the three-way test
in the June '83 issue. I remember that the conclusions expressed by those
who were involved in that test were mostly in favour of the muc ho flash
V-four Honda and the completely revamped GSX750 Suzuki. There was a
decided feeling of reservation, however, when it came to discussing the
delights of Kawasaki's new Uni-Trak GPz750. Although the GPz doesn't sport
the latest square-section frame of the Honda, or the quick steering 16-inch
front wheel of the Suzi. I liked the bike as soon as I clapped eyes on it.
So when we decided to test the kWack alongside the now fully-clothed GSX, I
just had to have some.
In comparison to the aforementioned cycles, the
GPz750 is on the surface, slightly archaic. The 738cc double overhead
camshaft engine has a family tree that goes back to the swift and
bullet-proof Z650 number of the late Seventies. Retained from that engine
is the eight-valve head (other manufacturers use 16 valve heads), the same
five-speed box and four 32mm Mikuni CV carbs which are common to the other
models in the Kawasaki range of the same capacity. But though you may say
that, on paper, the bike looks a little dated, in practice the GPz750 will
see off some 900s of a not-very-old vintage, and it will live easily with
the other 750s up to the quickest speeds at which most bods will ever
consistently travel.
Performance is smooth and rapid and, when
required, moves easily into the neck-breaking department. If the mood
takes you, a touring speed in the 100mph range is effortlessly accomplished.
Top speed is (as near as damn it) 130mph, and the GPz will cover a standing
quarter mile comfortably under 12.5 seconds. This is not a slow chariot.
Fast the bike is, but flexible it is not. As the
engine is more of a tweaked two-valve per-cylinder job, as opposed to the
four-valves-per-pot of the opposition, this bike is a decidedly revvy item.
Take-off requires more clutch dip and throttle blimping than most other
bikes, and it takes a little getting used to. When I first rode the bike in
heavy traffic, I tried to feed in the power with the same method I had used
on the GSX1100 Suzuki Katana I'd tested the previous fortnight. But without
clutch dip I nearly stalled on the lights before mastering the art.
Out on the country highways and byways, when the
GPz is into gallop mode, throttle response is immediate and urgent. At town
speeds and low revs, response is more like a wet fart. In town this got to
be a real pain at times as constant clutch dip and gear box thrash is not
what you really require. When you do move out of suburbia and find a clear
road ahead, the GPz is a pure joy to ride. Power output - a claimed 86
broncos at 9500rpm - offers great dollops of passing power and willingness
to over 120mph. High velocity cruising is about as effortless and
comfortable as you' re ever likely to find, thanks to large amounts of
rubber mounting for the engine, which continues the Kawasaki tradition of
supplying superbly smooth machinery.
Whether it's two-up cruising, town scratching or
having a quick blast through some tasty B roadery, the GPz steers precisely
and exhibits a taughtness that allows the rider to pick a line with real
confidence. The wheels are the traditional arrangement of 18-inchers back
and front, so there's none of the racer-quick steering of the 16-inch at the
front.
A simple aim and bank over is all that's
required. In line with the traditional feel, the frame is, as seen many
times before, the single duplex cradle variety. Suspension is the Kawasaki
firm's latest and greatest, with the single vertical shock with air
assistance, four-position damping adjustment at the back, and air-assisted
telescopic forks with adjustable anti-dive up front. Kawasaki was the first
of the big four to come out with a single shock and linkage system (remember
the company's late Seventies crossers), so it knows what it's about.
The back end, no matter what the setting, is
ideal for any type of riding you want to do, always firm yet progressive.
The front has an anti-dive that actually seems to work, as opposed to being
a marketing gimmick. On some bikes you wouldn't even know if it was there or
not, such is the feedback. The handling is taut and will forgive the odd
line change. Unfortunately, I can't say the same for the braking system of
twin discs at the front with a single at the back. The GPz7 50 is decidedly
over-refreshed when it comes to braking, or perhaps the designers were
over-refreshed when they came up with the system. The smallest digital
pressure will result in instant and vicious stopping - and often in a
lock-up. In the wet it's not a game to be recommended.
As for the clutch lever on the other side of the
instruments, its light and a veritable gem. The clutch, five-speed gearbox
and transmission is as smooth as the proverbial babe's twin cheeks. As
already mentioned, although the clutch and gearbox cop a right hammering in
town, neither could be faulted. I took a ride around the twistier lanes of
Kent and Surrey, changed gear more times than I can remember (it's safer to
use engine braking than twin anchs), and the system never faltered.
When you do set out on a lengthy bimble, which
is the best way to enjoy the GPz delights, the rider and passenger comfort
matches the best the others can offer. First impressions of the fairing were
that, apart from looking tasty and aerodynamic, it would be lacking when it
came to combating the elements. This is not the case. Obviously the lower
legs cop as much crap as they would if you were riding a naked cycle, but
wind and rain resistance for the upper bod is surprisingly good. Crouch
behind the bubble and the noise of the rushing air becomes almost
nonexistent. Straight line stability at the maximum speed mark is exemplary,
and turbulence between rider and fairing is kept to a minimum. Seating for
rider and friend is well padded, and the slightly crawl-up-the-tank front
end of the saddle allows the rider to tuck in when entering a bend. I've
encountered few bikes with clip-ons that haven't given the dreaded wrist
ache syndrome: the GPz proved to be a delightful exception. Although the
bike is definitely in the sporting category, a decent passenger grab rail is
supplied and positioning of the rear pegs is sensible and not, as now seems
to be the trend, so high that all but the smallest legs get shoved up around
the owner's waist.
Thankfully, the passion for digital speedos,
masses of warning lights and other associated gadgets seems to have passed
from the sport bikes and on to the mega touring models with bathtub fairings
and two-way radios. The GPz750 clocks are plain, simple and functional. What
warning lights there are sit atop the tank, which can be a little
distracting. I like the styling. Swooping lines from the front of the
fairing to the end of the neat tail-piece reflect the radical performance,
and the smart wheels and all black engine ontribute to the bike's appeal.
Although the GPz750 may not have the latest
16-valve engine, or the smartest ironmonger's delight frame, it is one tasty
cycle. The buzzing motor sucks more gas than the others (best 42mpg, worst
35mpg), but sports 750s are never gonna be frugal on gas if ridden in the
manner prescribed. At £2299, it's cheaper than the rest, yet it's no slower
or any worse looking,and its handlebars don't fall off. Need I say more?
RevelIe and the GSX score a fry and kick for
goal.
Suzuki's three-quarter-litre efforts have met
with varying degrees of approval since the four cylinder GS arrived in the
mid-seventies to an explosion of acclaim. It was the factory's first attack
on the big bike four stroke market. Weighing in at around 5051bs dry, it
could hit over 120mph from a claimed 68bhp and returned 39mpg. It also cost
only £1250... Compared with the other 750s it stood out by virtue of its
excellent handling and serious acceleration. As the seventies drew to a
close and the Orientals pandered to what they thought was an unquenchable
desire for megabikes on the part of their Occidental customers, the 750
class fell into, uh, desuetude. As though wishing to kill the class off for
good, Suzuki produced its first GSX 750 at the decade's end — within a year
it could hardly give them away. Overweight, overwrought and undersprung it
handled like an abandoned steamroller, though its motor was rightly praised.
In November 1980, its official price was £1700. I seem to remember Suzuki
offering them for £1200. The dohc 16-valve motor featured the TSCC (Twin
Swirl Combustion Chamber) mod, 32-mill carbs replaced the old 26mm versions,
CR was upped to 9.5:1 from 8.7, electronic ignition replaced the coil and
contact breakers and bhp was upped from 68 to 80.
Had it been mounted in a better chassis, the
early GSXs would have been in with a J chance. In 1983, Suzuki realised
this, being nothing if not quick on the uptake. The result was the GSX750ES,
a bike which did J very well in a giant comparisons" test with the direct
and revamped opposition from Honda and Kawasaki later that year.
For 1984, Suzuki has made I only styling changes
and added a "full" fairing to the 1983 model. It knows when it is onto a
good thing.
So do you, when you ride it. The stepped seat
seems low, perhaps because it places you in the bike, yet even with the
advantage of small wheels (16in front, I7 in rear) it is a tad over 31 in
off the ground. Not really low, is it? You'd expect from the styling to find
the bars somewhere south of the anti-dive; instead they are raised from the
headstock to provide a stance similar to the old upright bicycle position.
Odd, because you are actually leaning forward on them, as persistent wrist
ache in town testifies. Despite the confusion between assumptions and
reality, the riding position is excellent, comfortable and poised.
The fairing is effectively last years bikini job
with bottoms attached. The two halves hug the frame (aluminium painted
steel, square section where visible, tubular elsewhere) like shrink
wrapping, swelling a little down at the belly pan end to accommodate the
rider's bootiepoohs. The fairing's upper half is still about as useful as a
hankie in a hurricaine but it serves to make the bike look sharp. Pity the
instruments aren't mounted on the bracket— anything the bars have to carry
when steering should be mounted elsewhere if possible. The switchgear isn't
all it might be either. The indicator switch doubles as the main beam switch
and looks and feels flimsy. Gloved hands knock it right through from left
turn to right without knowing it. The horn doubles as the passing beam (for
the latter you haul the lateral switch back with the back of your thumb, ho,
ho. Should you still have the choke on - the engine takes some time to
warm up – you can launch yourself into a horn/flash/kangaroo mode peculiar
to learner car drivers…..) More thought here, please.
The niggles dissolve once the engine is warm and
the bike underway. The motor is all sweetness and light — light clutch,
light gearbox, smoother power — with the rasp ever present should the
throttle ever need tweaking in anger. In ordinary use the flexible motor
provides ample power to haul away easily from any troublesome moments. Whisk
it through the gears at max power and it rockets past such moments as though
on a different orbit. Wind it on from any point above 3000 rpm in any gear
and it'll restore your faith in life and in the value of fun. Drop a gear
and snap the throttle open and the rear tyre scorches for grip as you
catapult forward. Yet, delightfully, it idles at 500rpm, can be commuted in
top gear and limits its expression of temperament to a slight roughness,
almost unnoticed, from mid range to 8000rpm. You can feel it through the
pegs. Thick soles would damp it out. The power spread is wider than a
salesman's smile, the transmission smoother than a Brandy Alexander. Ridden
hard it returns some 37mpg. Ridden normally it's yielded as much as 56.
Overall I managed 46mpg whilst having a lot of fun.
It would be churlish, and difficult, to find
fault with the engine (though, at the risk of so being, wouldn't
rubber-mounting complete the good work?)
It would be hard, too, to find fault with the
chassis. The front fork has adjustable preload via a nut on the top of each
leg. The handbook warns against careless settings, stressing the need for
precision — I didn't find any need to adjust them in hundreds of miles of
test, either solo or two up, on good or average roads. The rear end is
Suzuki's Full-Floater affair. Preload is adjustable through five settings as
indicated by a near-invisible pointer, but as the adjustment method is a
knurled knob with no positive stop the exact setting is indeterminate
between the limits. Setting two is recommended (or as near to two as you can
judge). The book also recommends setting two for the four-position damper.
Odd, as the dial has the third position in red, suggesting it as standard.
In the event I rode mainly on the twos, bumping it up to threes for
passengers. Solo, the threes definitely made for a firmer ride. In the
interests of science I should have tried a 5/4 arrangement, I suppose, but
it takes a long time to wind the preload up. Anyway you don't expect me to
relate meaningful data about each of the 20 possible settings, do you? The
point is the bike will behave well as long as you adjust the rear end to
allow for extremes. Two 13 stone bodies need a little more beef beneath them
than one seven stone slimline tonic. The Suzi supplies whatever combination
you require.
I found the 16 in front wheel a mixed blessing.
In slow corners it is difficult to prevent oversteer - the system only
works when you power through bends, an impossible, not to say pretentious,
concept in commuting terms. The result is a scrappy feel to slow cornering
with a sort of pattering from the front wheel which reminds me of walking on
sugar. Nothing alarming, just a little irritating. As usual, the benefits
are felt out of town. Here the Suzi glides into long bends then clings to
the chosen line. Amending it is as easy as thinking about it. On a sweeper,
overtaking at high speed on slower-steering bikes usually requires good road
knowledge and a kind of apexing to bring you back into the curve. With the
GSX you simply flow into any trajectory that suits you at any point you
choose. It is almost uncanny. But, like everything else, you get used to it
so quickly that riding a slow-steering bike by comparison becomes almost a
chore. I'd go for the smaller wheel any time.
I wouldn't however, go for the Michelin A38/M38s
as fitted. Which Bike? has criticised these tyres before, and
Michelin has slapped our wrists for it. I personally hadn't ridden the tyres
and didn't know they were fitted until I looked to find out what could have
been responsible for a heart-stopping slide experienced shortly after
picking the bike up from Suzuki. I found nothing. Having no reason to
suspect the tyre (I've always found Michelins perfectly OK) I assumed it was
unseen oil on the road. Bu it happened again. Then one day I stopped for
fifteen minutes for a tea. It started to rain. At the first bend I nearly
lost it (and I am careful to the point of paranoia in the wet). Yet it
didn't happen again and the tyres felt grippy enough the rest of the trip.
After a while I began to notice that the tyres would slip, or at least, the
front tyre would slip, when it hadn't been warmed up enough. So if you stop
for any length of time, the tyre cools down. Again, and this is where the
risk is, if you suddenly drop into a tight bend, the tyre slides, because
the tread towards the edges just doesn't get hot enough in ordinary use.
Warm them up and, as you can see from our Bimota shot in this issue, they
stick like a pub bore. But they have to be warmed up well for that kind of
silliness. In ordinary use, I found them too unpredictable for comfort.
But the tyres can be changed, and with Metzelers
or MKII Phantoms the bike would be unnassailable in its class. Perhaps the
brakes could have a little more bite, particularly at the rear. But I had a
couple of involuntary emergency stops and each time they more than did the
job. And there's not a trace of grab. They're not Goldliners, but they're
pretty good all the same. The minor detail criticisms could only be remedied
by Suzuki, who oddly in other areas like the excellent petrol cap show a
flair for good design, but they do not detract from what is, for a
mass-produced machine, a lovely motorcycle. It has spirit and even a touch
of class. Improve the fairing and fit a grab rail and you'd have a superb
cycle. Fat chance of Suzuki knocking this one out cheap.