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Yamaha XS 750 Special


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Make Model

Yamaha XS 750 Special

Year

1978

Engine

Four stroke, transverse three cylinder, DOHC, 2 valves per cylinder

Capacity

747 cc / 45.6 cu-in
Bore x Stroke 68 х 68.6 mm
Compression Ratio 9.5:1
Cooling System Air cooled

Induction

3 x Mikuni BS34-II constant velocity carburetors

Ignition

Electronic TCI

Starting

Electric
Clutch Multi-plate, wet

Max Power

50.4 kW / 69 hp @ 8500 rpm

Transmission

5 Speed 

Final Drive

Shaft
Gear Ratio 1st 14.63 / 2nd 9.48 / 3rd 7.76 / 4th 6.53 / 5th 5.71:1

Rake

27°

Trail

114 mm / 4.5 in

Front Suspension

Telescopic forks, adjustable, 36 mm

Front Wheel Travel

176 mm / 6.9 in

Rear Suspension

Dual shocks swing arm, 5-way preload adjustable

Rear Wheel Travel

102 mm / 4.0 in

Front Brakes

2 x 267mm Discs

Rear Brakes

Single 265mm disc

Front Tyre

3.25-19

Rear Tyre

4.00-18

Dry Weight

230 kg  / 507 lbs

Fuel Capacity 

19 Litres / 5.0 US gal

Oil Capacity 

3.8 Litres / 4.0 US qts

Consumption Average

5.2 L/100 km / 19.1 km/l / 45 US mpg

Braking 100 km/h - 0

42 m / 138 ft

Standing ¼ Mile  

13.1 sec / 163 km/h / 101 mph

Top Speed

187 km/h 116 mph

The decade we blame for bell-bottoms and Abba is also responsible for the birth of the factory "special" and the fore fathers of the modern cruiser. Before the Seventies the only specials or customs rolling out of motorcycle factories were purpose built race machines. Boulevard cruisers were the realm of bike customizers and motivated enthusiasts. But the Age of Aquarius changed all that as the Yamaha XS750SF, this month's used bike, shows.

One of the earliest examples of a factory custom was the Harley Superglide. It had long forks and bobbed fender, but in spite of its poor sales was a sign of things to come. For it wasn't long before many companies were building specials. The Japanese with their dominance of the US market were no exception, every brand from the Land of the Rising Sun had one. The XS750SF "Special" is a prime example.

The XS line from Yamaha featured a full line up, from twin cylinder tiddlers like the XS360 to big bore road bikes like the XS1100. Now don't let the XS moniker fool you, these bike were neither extravagant in features nor blessed with overabundant power. I guess it was just a name. The XS750SF falls in the middle of this line up, meant both as a machine for Saturday night cruises of the boulevard and cross-country trips. And the SF part of the name meant it was badged as a "Special" and received certain extras from the factory, but more about that later.

The three cylinder motor found on the XS750 is a strange duck. It was never a popular setup until the Seventies when the British, Japanese, and Italians all offered their own version of the triple. After that they fell out of favor until being resurrected by BMW and then Triumph.

The odd feeling of a three-banger comes from the dual life it leads. It tries to blend the torque of a twin with the fast revving horsepower of an in-line four and in my opinion does an all right job of it. The XS750 is no exception, it's strong running right off the line and makes a fair amount of power through its rev range. Not to say that it's a tire shredding beast, but rather a competent motor for hauling around a rider or two and their gear.

Fairly basic by design Yamaha's triple is air-cooled with twin overhead cams running two valves per cylinder. The transmission is the usual five speed with a shaft for the final drive. The tranny and motor are reasonably reliable except for 2nd gear which has a habit of destroying itself and the motor is very sensitive to substandard fuel (read below 92 octane). Low grade gas will cause knocking, pinging and fouled plugs, but keep it well fed and it will reward you with miles of uninterrupted service. But I must add the addition of fresh plugs and some octane booster to the 750's tool kit is always wise.

As may be apparent from the lines of the XS750, it was the father of Yamaha's hugely popular Virago series, which continues production nearly twenty years since its introduction. And this by default makes it sort of the father of Japanese cruisers. The chopperesque raked out front end made the XS a stable ride on straight roads but did nothing for the confidence of the rider in any corner.

The frame was a simple double down tube style and was semi-rigid for its day. But that didn't matter since the long forks and average rear shocks were not intended for anything but straight roads. The frame also has a tendency to "wind up" in corners. This is the way a frame flexes to the side like a spring in corners and then snaps back when upset by a bump.

The three into two exhaust blats out a sort of exploding raspberry sound through the shorty megaphones when on the road and they hang low enough to touch down very easily.

As mentioned before the XS750SF "Special" had certain parts installed at the factory to give it that one of a kind built by the thousands look. Twin disk brakes up front and a disk rear brake were standard on the SF and they worked very well, but it is really hard to ride the bike fast enough to take full advantage of all that Seventies dinner plate brake disk technology.

Another "custom" item for the SF were the big buckhorn bars which had a certain appeal in times gone by, but now only flex pitifully and contort your wrists. The bike was topped off by a wide bucket style seat although the one I rode had been replaced by an after market saddle. The fuel tank is a long teardrop shape, holding five gallons, and just so no one would miss what you were riding--the side panels were emblazoned with the words "Special 750".

When the rubber hits the pavement one thing is clear. The SF is supremely at home on wide open flats like the straight roads of the Dakota's. This is where traits like soft suspension and straight line stability are enjoyed not admonished. The seating position is comfortable, even for tall riders but the bars bend your wrists to odd angles. Long hours of riding is possible but a backrest would make that easier. Still it is fairly competent for around town duties, not being too much of a bike to maneuver through city traffic.

As a used machine the SF is a fair bike if it's been maintained properly, with good clean examples going for around a thousand dollars. Be wary of ratted out barn fresh examples though since they usually cost more to fix than they are worth. Don't pay much more than a grand for one either, no matter what the owner says it is not a rare bike with huge historical significance. Some of the other problems to look for would be leaky petcocks, once they start leaking they never stop, and the voltage regulator is notorious for going soft. But other than that the XS750 and its big brother the XS850 are good values for a rider on a budget and well preserved examples will reward their owners with years of service.

Source by Victor Wanchena