1975 Suzuki GT380M Sebring - 8-Page Vintage Motorcycle Road Test Artlcle

Description

1975 Suzuki GT380M Sebring - 8-Page Vintage Motorcycle Road Test Artlcle
Original, vintage motorcycle article
Page Size: Approx. 8" x 11" (21 cm x 28 cm) each page
Condition: Good
SUZUKI GT380M SEBRING
Plain Jane strikes again
“Japanese motorcycles are all alike.”
That used to be a popular saying among
bikers who thought the only real motorcy-
cles came from the good old U.S., or at
least from across the Atlantic, not the
Pacific. And although all Japanese motor-
cycles are not now and never have been
alike, they did and still do have some
notable similarities.
The major areas in which they are noi
similar is their concept and planning, even
though they display many likenesses in
their external construction and appear-
ance. The philosophies and methods
maintained by each company’s engi-
neering group accounts for the state of
the finished product. So even though a
lot of the bikes look alike and share what
appear to be the same technological ad-
vances. they possess quite dissimilar per-
sonalities.
For example, some companies are ex-
tremely horsepower-conscious. They seem
to care more about horsepower figures
and quarter-mile limes than about han-
dling and ease of riding. Others lend to
be very gadgel-oriented. being the first to
incorporate every' new little doo-dad or
invention to come along. And still other
companies concern themselves with relia-
bility. maintainability, and rideabilily.
rather than a performance image and
space-age wizardry.
Suzuki appears to fall into the latter
category: conservatism. They haven’t built
an ultra-high-performance street bike
since the 250 X-6 Hustler of nearly a
decade ago. However, they’ve had their
share of “firsts” and innovations.
Suzuki pioneered the large-displacement
two-stroke twin with the T-500 in 1968
but instead of building a super-fast rock-
etship as they surely could have, they gave
it a wide powerband, lots of low-end
torque, and a conservative rpm redline.
They introduced the first water-cooled
two-stroke street bike in 1971. the GT750:
even though it appeared right in the mid-
dle of a superbike war, it too was a con-
servative, low-revving torquer. And just
a month or two ago Suzuki unveiled the
RE-5, the world’s first mass-produced ro-
tary-engined motorcycle. But even the
RE-5, with tremendous horsepower and
performance potential, was built with this
same conservatism, at least mechanically.
The RE-5 is a rather curious experiment
in styling. But otherwise, conservative ap-
pearance. cautious engine design, and a
concern for longevity instead of sheer
performance have ultimately taken over
the Suzuki street line, including our test
bike, the GT38O Sebring. No. Suzuki was
not the first with a two-stroke triple, and
theirs are not the fastest. But they weren’t
engineered to be the fastest, just like they
weren't styled to be the flashiest and
PHOTOGRAPHY BY ART FRIEDMAN
Suzuki's Ram Air System forces
cooling air deep into the fin cavities
for increased heat dissipation.
weren't designed soon enough to be the
first.
We tested the GT550 several months
ago and it impressed us considerably.
Since it was built along these same mod-
erate guidelines, we were eager to find
out if the 380 was as good as its big
brother. It would have to go some to be
better.
THE BIKE: The 1975 Suzuki GT380M
Sebring bears a close resemblance to last
year's L model and looks very much like
a smaller version of the GT550 we tested
for our November issue.
Like the 550, the 380 uses a one-piece
head that has three separate combustion
chambers. A cast aluminum shroud which
composes the Ram Air System sits atop
the head. The shroud forces additional
cooling air between the head fins, espe-
cially those of the center cylinder, for
more efficient top-end cooling.
T h r e e s e p a r a l e cy I i n d e rs m o u n l b e n c a l h
the head, and each uses a standard three-
port layout. A square (the bore diameter
equal to the stroke length) 54mm bore and
stroke yield a 37lec displacement. Mild
port timing coupled with the mild 7.2 to
1 compression ratio helps increase the
380's engine dependability.
A pair of helical-cut primary gears
transfers power from the crankshaft,
through the twelve-plate wet clutch, and
into a six-speed gearbox. The gear ratios
are evenly spaced for the most part, with
the biggest gaps between the lower gears.
The power exits the gearbox on the left
side of the engine, where a 15-loolh trans-
mission sprocket sends it down a #530
chain to the rear wheel.
Three 24mm Mikuni slide/needle car-
buretors handle the fueling chores. Each
is rubber-mounted to its respective cylin-
der. but all are joined together by a long
common lop and a permanently synchro-
nized throttle linkage. Once the carbs are
synched, they stay that way since the link-
age can't stretch or change because of
improper cable routing. Two cables run
from the twist grip to the linkage; one
pulls the slides open, the other pulls them
closed.
A rubber boot attaches to the rear of
each carb and runs to the airbox under
the rear portion of the gas lank. Two
washable oiled foam elements fit inside
and provide clean air to the system.
The 380’s exhaust system is similar to
the 55O's except that there aren’t any
equalizer tubes between (he header pipes.
The two outside cylinders have their own
separate pipes with welded-on mufflers,
but the center pipe forks beneath the
engine and connects to two smaller
mufflers. One of these mufflers runs to
either side of the machine, giving the bike
a balanced look.
The GT380’s breaker point mechanism...
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