Few
bikes have arrived to such a warm welcome as Yamaha's first big
four-stroke superbike, the XS750 triple, whose performance,
distinctive style and versatility made it highly rated by press and
public alike on its launch in 1977. And fewer still have followed
that initial impact by fading from the scene quite so quickly, having
failed to make a mark on a superbike market that was suddenly awash
with high-quality alternatives.
On
paper, the Yamaha looked a winner to its last, carefully considered
detail. The basics were very much in place. Its engine was a 747cc
air- cooled triple with twin overhead camshafts, a 120- degree
crankshaft (for smooth running) and shaft final drive. Yamaha's
designers had kept the engine compact
by using bevel gears to turn the crankshaft's drive through 90
degrees for the drive shaft. With a maximum output of 64bhp at
7200rpm and plenty of mid-range torque, the triple came very close to
matching its sportier chain- driven four-cylinder rivals for pure
power.
This
unique engine was matched to rounded, distinctive styling and a
relatively conventional but cleverly designed chassis. The
twin-downtube steel frame employed substantial bracing around the
steering head, in the fashion of the BMW's R75 twin. Forks and twin
rear shocks were typical Japanese items. The Yamaha was rather tall
and it was heavy at 5141b (233kg) dry. But it was also well
appointed, with a roomy riding position, clear instruments and
self-cancelling indicators.
Straight-line
performance was undeniably impressive. The Yamaha 750 motor was smooth,
tractable and powerful, sending the bike to a top speed of 120mph
(193km/h) and allowing effortless high-speed cruising. Its
three-cylinder layout gave a pleasant character, with the bonus of a
distinctive exhaust note. And the XS had an efficient five- speed
gearbox as well as its shaft final drive system, itself a real
benefit in the days of fast- wearing drive chains.
That drive
shaft had almost no adverse effect on the Yamaha's handling, which
received much praise although the bike was designed for comfort as
much as for agility. 'We failed to make it waggle, weave or twitch
and we tried our damnedest,' enthused
BIKE
magazine experienced tester, who summed up the XS750 as the best
Japanese bike and best all-round touring machine he'd ever ridden -
including numerous more expensive BMWs.
YAMAHA 750
YAMAHA 750
Comfortable
cruising
Long-distance
comfort was good by the standards of unfaired bikes, thanks partly to
the generously padded dual-seat. One criticism was that the fuel tank
was too small for touring, but this and the poor headlamp were the
only criticisms, apart from the mediocre wet-weather performance of
both tyres and disc brakes, which was typical at the time. Given the
Yamaha's very competitive price, it looked set to become a big hit.
But
the motorcycling public decreed otherwise, partly because of the
rival attraction of fours including Honda's proven CB750, Suzuki's
new GS750 and Kawasaki's cheaper Z650; and partly because the Yamaha
quickly earned a reputation for unreliability. Troubles included
piston ring failure, seizure of the central cylinder, rapidly wearing
primary drive chain and ignition points, plus the gearbox's
occasional trick of jumping from fourth straight into first.
suspension.
But the damage had been done, and neither that model nor the revamped
XS850 that followed two years later could bring Yamaha's triple the
success that had once seemed so assured.
Word of
the unreliability spread, and the XS750 never recovered. Yamaha made
a series of updates to cure the problems, and in 1978 improved the
triple with the XS750E model, which had an extra 4bhp, revised
lubrication system and uprated front brake.
YAMAHA 750 prices 2014
MINT $6,000 $8,000 £5,000 £7,000
GOOD $5,300 £4,800
FAIR $3,700 £3,000
PROJECT $900 £500
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