Yamaha XS 650
Yamaha XS 650
Air cooled, four stroke, parallel twin cylinder, SOHC, 2
valves per cylinder.
Bore x Stroke
75 x 74 mm
2x Mikuni carbs
Battery, induction coil /
electric & kick
50 hp 36.4 kW @ 7200 rpm
54 Nm @ 6800 rpm
5 Speed / chain
2x 267mm discs 1-piston calipers
Yamaha finally walks all over the boys from Britain
Original article appeared in Big Bike magazine March, 1976 issue
At about this time last year, we had the experience of testing the ‘75 Yamaha
XS650B, which was, then, Yamaha’s only entry into the big-bore market. And it
was a pleasant experience - much to our surprise.
We had long heard (and told) stories of how the early Yamaha 650s were not
exactly what the makers had promised. Owners sighed loudly about excessive
vibration, case and carb leaks, evil handling. All but the last of these
ailments were shared by the very bikes that Yamaha was trying to compete with -
the British twins.
With the introduction of the ‘75 XS, things took on a new perspective. The
majority of the flaws that had plagued the bike were corrected; the engine
received more attention to vibration isolation and the bars, footpegs and fender
(to name but a few) were all insulated from vibration via small rubber grommets
between the component and its respective mounting surface. The cases were sealed
up tight (using Yamabond #5 - which is now the rage among Triumph fans) and case
leaks were a thing of the past. Certain carb revisions were also made in the
interest of reliability. And the handling improved somewhat, although it was
still nowhere near the Triumph goal that was being aimed for.
In general, the bike was very impressive. Quality control was enforced to such a
degree that there were no areas left in the rough. Styling was up above the
British marques, utilizing Bauhaus-type thinking: clean, functional lines
-nothing there that shouldn’t be there.
Upon writing the test, we gleefully exclaimed that the Yamaha XS650B seemed to
have reached a zenith in its evolutionary cycle. We didn’t really expect that
Yamaha would delve into more improvements on the machine, since they had a
decent package as it was, and they were already spending plenty of money on
So when Yamaha’s press releases on the ‘76 XS650C arrived, we weren’t expecting
too much in the way of changes. These press releases, being what they are,
didn’t really give too much hard-core information, but from what we could see,
the bike was basically identical to the B-model, except for paint and trim
changes. We can all be wrong once in a while . . .
When we finally got the C version of the 650, those ideas about a repainted ‘75
started to fade.
The bike actually received a lot more than just a passing fancy from the design
department at Hamamatsu. While walking around the bike and giving it a visual
once-over, some major refinements came to view immediately: the previous model’s
disc brake arrangement -one of the best anywhere - was gone over and reworked.
The caliper - which resembles the old model markedly - has been mounted in a new
position aft of the fork slider, and is now on the right-hand side of the
machine. The change over to the aft position is said to increase caliper
rigidity and stability, while moving some of the unsprung weight closer to the
center of the bike (more later on how well it works).
Another noticeable change is with the exhaust system. Last year’s model had a
set of mufflers that closely resembled a cross between those of a Norton
Interstate and a BMW R/75. They gave off a somewhat loud (for a production
machine) exhaust note, which was perhaps a little too loud to be listened to for
long periods of time. The new mufflers on the ‘76 are a direct hand-me-down
(up?) from the XS500. Even the identification numbers on the mufflers are the
same as those on the 500. A cross-over tube has been added just ahead of the
rear wheel, at the junction between the header pipes and the muffler inlets. The
mufflers are upswept in the same manner as on the 500, supposedly adding ground
clearance while cornering, and definitely affecting the styling of the machine.
The exhaust note is medium-quiet, with a very pleasing, throaty rumble.
Another item that is readily noticeable when looking at the bike is the new
instrument layout. Last year’s “dashboard” arrangement has been junked to make
room for two British-looking barrel-type instruments that are mounted separately
from each other rather than combined in one common pod. The British styling of
the tach and speedo is quite tasteful but . . . Yamaha couldn’t leave well
enough alone, and added an “ignition switch and idiot light cluster” in between
the two units. This item looks a lot like a plastic replica of a Japanese
pagoda, and really spoils the looks of the two gauges. (What was that about
The fuel tank looks pretty much like last year’s, but is now fitted with a low
profile lockable fuel cap (no doubt federally inspired), and a paint job that
looks a lot cheaper than the previous scheme. A solid coat of what Yamaha calls
“French Blue” is accented with contrasting panels and stripes. Not too awfully
tasteful - probably a change just for the sake of change. Another thing that
looks cheap is the overall attention (read: lack of attention) to detail this
year. The welds no longer look as even and smooth as before, and little corners
have been cut here and there to save money. For example . . . where the
headlight ears are spot-welded to the fork tube covers. Last year the resulting
seam was filled in and smoothed over before painting giving the impression that
the two parts were actually one. This year, the two parts are simply welded
together, and then painted. No fill-in, just an ugly seam - small quibbling, but
One interesting change that stands out quite clearly is Yamaha’s new choice of
tires. They’re a matched set of Yokohamas, with a unique wrap-around tread
design (more later on how they work). A feature that is probably a result of DOT
pressure is the “tire wear indicators” incorporated into each tire. This
“indicator” is a thin red strip of rubber molded into the tire; when the tire
has worn almost to the limit, the red stripe becomes visible. Tire wear
About the last item on the “visible changes” list is the reworked linkage system
on the two Mikuni carbs. Last year the two constant-vacuum units were more or
less separate of each other, each having its own cable and idle adjustment. This
meant that the two carbs were not always, in perfect synch, due to vibration and
uneven cable stretching. The new setup is somewhat like what you might find on a
Honda Four, but with two less carbs. The CV Mikunis are mounted solidly on a
common backing plate of cast alloy, with a short linkage connecting the two
butterfly valves. A single cable actuates both units, so synchronization stays
the same at all times. One common idle adjustment also controls both carbs, so
both carbs will be operating in a like manner even at an idle.
The engine itself is unchanged from last year’s model, and with good reason: all
of the maladies that had plagued the 650 mill in the past were rectified in the
last year, and the result was a good, clean, powerful engine, that for all
practical purposes comes very close to being indestructible. Just keep putting
in low-lead and a little oil, and the thing will run forever.
Riding the bike is nothing at all like it used to be. The first hint of change
comes when you sit on the machine. The overall height of the bike is a couple of
inches lower than it used to be, and the feeling is a lot like that experienced
on a Triumph or Norton. All of the controls are in the right places: The bars,
which have been changed over last year’s, sit considerably lower and narrower.
The seat - one of our major gripes last year - has been assembled with new
padding that gives way much easier. The result is that you sit lower on the bike
- and not halfway up the tank like you were forced to on the old versions.
Starting procedure is easy enough, just engage the enrichener (which only
affects one carb), push the button or kick it through twice, and the thing
starts running right away. Although the old models were notoriously
cold-blooded, the C-model warms up right away. The first block or two of your
morning riding can be done with the choke on, then it can be released and
operation is normal.
One thing that we noticed right away is that the bike runs much smoother than it
ever has in the past. For all intents and purposes, there is no annoying
vibration whatsoever. Additional rubber mounting grommets see to that. The bars
and pegs are well insulated from the engine’s vibrations; about the’ only
detectable vibration comes from the gas tank if you happen to touch it with your
A very charming trait of the 650 powerplant is its incredible torque. Moving
away from a dead stop is almost a matter of simply releasing the clutch. Little
or no throttle is actually needed to get underway -the bike simply starts
pulling almost from an idle. When you do crack open the throttle, though, things
start happening fast. Once the power really comes on strong (at about 5800 rpm)
the bike runs like a scalded cat. Winding out all five of the Yamaha’s
constant-meshed gears will result in a top speed of 118 mph - which is pretty
much unheard of for a Japanese bike in the XS’s class.
Riding around town is more or less effortless, with the possible exception of
clutch operation. It’s just a wee bit stiff for our tastes, but then again,
there was never even the slightest sign of plate slippage throughout the
duration of the test. Maneuverability in city traffic is excellent - just point
the machine in the direction you want - and it goes there easily and
predictably. Darting in and out of traffic presents little in the way of
problems, thanks to the Yammie’s light and responsive steering.
On the freeways, the Yam shines well in all areas except one: rain grooves.
You’ve all heard us griping about these nasty little slots in the freeways’
surface, and the 650 inspired more than a few comments on the subject. At a
steady 55 or 60 mph, the front tire shimmies and shakes from side to side, and
tends to follow the pattern of the grooves rather than the course that you had
planned for it. While this trait isn’t hazardous, it’s not particularly
reassuring either. Once you get onto some normal highway, the bike is as solid
as a rock. And for a change it’s comfortable, too. We had the pleasure of
racking up some 2000 miles on the highway with the Yammie, and were never caught
complaining of back pains (or butt pains either, for that matter).
Where the 650 really feels at home, though, is up in the canyons. At long last,
the engineers at Yamaha have come up with the perfect combination for the
six-and-a- half to put it up in the same league with the British twins.
Everything about its handling says “British.”
Stuffing the Yam into hard, fast curves is an experience that is hard to
describe. Everything feels right. The bike does what it’s supposed to do, and
without any complaints. When roaring through long, super-high- speed sweepers,
it tracks straight and true, without the usual wobbling that we’ve often come to
expect from Oriental iron.
And those tires - the ones that were such a bitch on the freeway -have got to be
among the best we have ever found on a stock Japanese bike. They stick like
crazy, and have no tendency to let loose without warning. Very, very good tires
-good enough to buy twice.
Aside from the tires, there have been a couple of other changes that contribute
to the bike’s superior handling. The front end has been completely reworked, and
features a newly-designed set of sliders, it has been fitted with altered-rate
springs, and some work has been done with the hydraulic damping valves. The end
result is something that comes very close to a Japanese version of Cerianis or
Betors. The rear shocks have received some updating as well. We don’t know what
the hell they’ve done inside those units, but whatever it was, it worked. The
Yamaha 650 is one of the few Japanese bikes that we wouldn’t change the shocks
on. They are simply great just as they come from the factory.
There is no detectable flex in the frame whatsoever, since gussets in key areas
keep things rigid. The only limiting factors in the Yammie’s handling are the
cumbersome sidestand and (ugh) centerstand. Although the side unit can be
modified to keep from grounding, the centerstand is something that should come
off right away - it simply grounds too easily.
In general, the bike’s handling will encourage its owner to spend a lot of time
play-racing in the hills. The overall feeling of the bike inspires confidence
even in the novice rider.
And it’s safe, too . . . .
As the 650 comes from the factory, it has possibly the finest set of binders to
be had anywhere. The newly-designed front hydraulic disc is very, very effective
- without being too grabby. The feeling that is relayed through the lever is
similar to that of a dual leading shoe brake, but since it’s a disc, it stops
you a lot faster. After repeated panic stops from 40 and 60 mph on our test
section, the disc never overheated or failed to haul the bike to a straight,
safe stop. The rear single leading shoe brake is more than adequate, and it too
never had the slightest tendency to fade.
One almost shocking item is the Yammie’s price tag - it has actually gone down!
This year’s 650 (at least here in California) is going for a measly $1544 before
tax and title. This is more or less unheard of in this day of
recession/inflation . . . but Yamaha is making a serious attempt at taking
control of the street bike market (or at least getting a chunk of the action
away from Soichiro Honda, King of Street Sales). With their ‘76 street lineup,
it seems quite altogether possible, too. The line currently consists of the 360
four-stroke twin, the 400 twin (updated RD350), the XS500, the XS650, plus the
three-cylinder, four-stroke XS750.
Being now the second largest bike Yamaha offers, the 650 should still enjoy
healthy sales figures. For the price, the prospective 650 buyer is getting a lot
for his money: reasonably good styling, excellent performance and handling,
economical operation (45-50 mpg) and undisputed reliability.
We’ll be watching the street market very closely this year, and we expect to see
a lot of ‘76 Yam 650s out there with the best of ‘em.
Source Big Bike" March 1976