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►Visually, the 380 mostly
makes it as a Gran Tourismo. It's big and massive and heavy looking, dense and
compact. Following the GT design theme, the 750, 550, and 380 are all very
similar in component shape, instrument/control layout, and finish. If pictures
of the three were compared, with the engine areas blanked out, you would have a
hard time figuring out which bike was which. The colors and tank panel designs
and badges differ, and one has a radiator, but that's about it.
The fuel tank adds a lot to the bulky, squat look of the 380.
Its squarish corners and barrel-chested depth complete the illusion.
Even the
white accent splash is created to give a blunt-headed massive frontal attack
effect, the Suzuki badges on both sides of the tank are separate metal castings
that look somewhat nicer than the decal or painted-on type. A wide, deep center
saddle in the tank saves the bulk for illusion: fuel capacity is a moderate four
gallons. The tank's saddle space is occupied by three ignition coils and the
very Norton Manx-looking frame-tubing pyramid. A very nice flip-up filler cap
has a key lock on its release button. Suzuki says that they have traced a lot of
their warranty problems to tank additions by owners' enemies. The cap seals
absolutely perfectly.
Other
painted pieces are the headlight shell, the upper fork covers, and the side
panels. The side panels don't do all that much for the gut-level visual reaction
to our machine. Phony air vents molded into the ABS plastic and pointy-toed
corners make the covers look extremely forced. The two colors available are
Jamaica Red and Hawaii Green. The frame is black. A tasteful use of bright
polished surfaces balances the black and colored paint.
One of the
first things that strikes your eye on the 380 is the cast aluminum shroud that
is fastened to the tops of the cylinder heads. The shroud lifts to form a high
scoop over the center head. When Kawasaki introduced their three, overheating
problems were encountered by owners who changed the front fender or added an
accessory in a place that partially blocked air flow to the cylinders. The
problem became critical only when the atmospheric temperature was very high, but
torque was reduced substantially in the non-critical zones. Last fall, Suzuki
experimented with air-directing shrouds on their road racers at the Ontario AMA
National. By using the shrouds, they were able to use higher compression ratios
without suffering from overheating. Carefully instrumented tests showed that
like increases in torque were to be had from the 380 at high cruising speeds on
the highway. Vibration noise, mechanical fatigue, and expansion rate problems
are all alleviated by using silicon rubber grommets between the one-piece shroud
and the three individual cylinder heads. The tops of the sparkplug caps are
sealed, like those on a VW, where they pass through the shroud. Contrary to the
advertising term used by U.S. Suzuki for the shrouding (Ram Air Induction), the
system has no direct effect on the carburetion or cylinder inlet systems.
As on the
GT-750, the center exhaust pipe splits to feed two mufflers that are smaller
than the single systems on the sides. The reason for this split seems to be more
for looks than anything else. Four look better than three. The exhaust systems
are beautiful, sweeping gracefully from the cylinders and tapering gently into
the mufflers. At the ends of the mufflers, they taper back sharply to form a
reverse cone.
Inside, the
engine is put together in a very straightforward way: none of the spatial
trickery of the GT-750 is employed. In fact, the 380 engine is very similar to
the Kawasaki threes internally. The 380 is virtually an X-6 Hustler engine with
another cylinder grafted to the left side. The bore and stroke are the same, and
cylinder layout is identical except for minor porting differences.
Primary
drive is via a helical gear on the right end of the crankshaft, which mates with
a gear on the back side of a wet clutch. The clutch turns the mainshaft, the
drive sprocket is on the end of the layshaft, and in between is a six-speed
gearbox almost identical to that of the X-6.
A lot of
two-strokes have the breaker-points on the end of the crankshaft. Many of them
suffer from ignition timing variances when the engine gets hot and the
mainbearing clearances increase. The 380 avoids that trouble by having a
separate breaker assembly drive that is nylon-geared to the right end of the
crankshaft. The assembly has its own double ball bearing support, which results
in consistent ignition timing and a resulting consistency in engine performance.
The
alternator is driven directly on the left end of the crankshaft.
Starting our
GT-380 was always a one-kick operation. The fuel valve is a diaphragm-type
automatic metering affair that does not require closing each time you park the
bike: the diaphragm is operated by pulses from the inlet manifold, and no fuel
flows unless the engine is running. Pulling a small lever on the left hand grip
enriches the carburetor metering for cold engine starts. A flick of the ignition
key, perched up between the speedometer and tach, allows primary current to flow
into whichever coil happens to have its points closed. There's an emergency
thumb-operated ignition switch on the throttle assembly, so you must see that it
is in its on position. Then, one jab on the kicks-tart lever pedal does it every
time.
Soon, the
three settles into a familiar, but deeper-throated, bum-bumidy-bum-bum
two-stroke idle. Ah, that seat is nice. At a mere 31-inches off the ground, it
would allow our six-footer to sit flat-footed. Things even out in the engine
after about three minutes. A six-pound pull on the clutch lever (easy) and a
push down on the left foot pedal lets the little green light in the tach go out,
and you know you're in first gear. You wouldn't know otherwise, for there's no
clunk or clash to tell you. The engine stutters a little and you have to slip
the clutch out just a skosh. Changing up through the gears, click, click; there
are no rude clunks to spoil all of those nice clicks.
Even after
several miles, considerable smoke continued to pour from the pipes.
Eventually
it dried up for steady throttle cruising, but a burst of acceleration would
renew the stream of blue smoke. Suzuki calls their automatic fuel/oil mixing
system Crank Cylinder Injection (CCI). In this system, oil from a separate tank
feeds a mechanically driven oil pump. Delivery rate from the pump is governed by
both engine speed (rpm) and throttle opening. That way, the engine gets oil
metered in direct proportion to the load to which it is subjected. For the GT
series, a sub-system has been added to work in conjunction with the CCI. One-way
valves in the bottom of the crankcases of each cylinder are connected to the
transfer port of the right cylinder with small neoprene hoses, the theory being
that any residual oil in the cases will be drawn into the cylinder and used
faster than if the oil were allowed to be slowly washed out by the fuel/ air
mixture. The way our bike smoked at the start, and continued to smoke, there
must be some hitch in the scheme. Little puddles of oil collected in the ends of
the mufflers after each ride.
Our first
riding impression of the 380 was the unexpected smoothness of the engine. The
feel is much like that of the GT-750, and for good reason: the engine is
fastened to the frame via rubber shock mounts in both bikes. We think this
mounting system is a good thing. The only bike having a similar system in the
350 comparison test (Cycle Dec. '70) was the Bridgestone GTR. In all the other
350s, we could feel all the little effects of secondary vibrations in the
engine. The Bridgestone was the first bike we thought was "turbine smooth." The
GT-750 Suzuki was the next. In the 380, you can feel the engine go through its
stages of harmonic vibration, as the revs range, but the feeling is remote and
very low-key. The only place that gets into really constant bothersome vibration
is the passenger footrests. The footrest mounting bolts double as the rear
muffler fasteners. There is a Silentbloc-type rubber mount on the mufflers, but
the passenger pegs are on the muffler side of the rubber. As a result, the
footrests shake really badly. The rider's footrests go through ranges of
moderate tickle during hard acceleration, but are smooth at all cruising speeds.
The remainder of the bike that touches the rider is free from bothersome
vibration. The engine still shakes normally, but the rider doesn't feel it.
The GT-380J
has a big motorcycle feel. Steering is slow and deliberate when compared to the
350s as a group, and light and responsive when compared to the 750s. Handling is
great. Out in the mountains, twisting the bike as hard as possible, the 380's
steering and suspension work in perfect harmony to provide a surprise-free ride.
It's great fun: the throttle full open when you're not on the brakes, and
thrashing on the pedal of that six speeder.► |
Bike Tests 
