Long
distance test XZ550
Test published in MOTORRAD 3 August 1983
The test XZ (a naked 1982 “Euro” version) on a racetrack.
A real thorough test of an
XZ550 was published in the German MOTORRAD (Die
grosse Motorrad-Zeitschrift).
The test was a 25.000 km (ca 16.000 miles) test in the country of the speedlimit-free Autobahnen with trips to
Most of this test is
translated by XZv2. Keep in mind that this is a test of a Euro-version of the
XZ 550 under European conditions of 1983. At the end of the test the complete
motorcycle was dismantled and all parts checked for wear and problems.
Remember I am not a
professional translator; my native language is Dutch, my knowledge of German is
limited. If I have doubts on the meaning, I also give the German word(s). The
title is the first problem.
WEIT GEFEHLT (big failure and/or it offers not enough by a large margin)
She is the victim of her
marketing strategists. The Yamaha XZ 550 was sent to the race-track with the
reputation of Supersprinter, although she has in the
first place stayer-qualities.
Fall 1981,
premiere of the new Yamaha XZ 550.
The Yamaha advertisements spoke of the dream-V, in association with the actress
with the name Bo Derek. And her film role did not go better than that of the XZ
550 – both became a total disaster.
A total number of 441 XZ of
the 64 horsepower version* was sold up to now in
The poor Yamaha had to
compete with a Honda CBX 550 and with a Kawasaki GPZ 550, without having even a
trace of a chance. The XZ
had to offer, also during
the initial stages of this test, a poor 180 km/h (112 mph) against both
full-blooded super-sport four-cylinders, both reaching speeds of ca 200 km/h
(125 mph).
Already the first
measurements indicated problems, that the riders of
this 25.000 km test would have. The compression ratio in the two cylinders
varies unnecessary much with 9 and 10,5 bar, respectively, and the speed
difference of 184,5 km/h and 165 km/h only caused by the difference of riding position suggests a too low gearing
for 5th gear.
How much too low would only
turn out during long distance trips bringing the motorcycle to
Permanent full throttle in 4th
gear near the red zone of the tachometer was necessary to reach acceptable
averages, and the fact that the XZ survived such heavy conditions, is worth a
compliment. The engine had under these conditions sufficient internal cooling:
both vertical carburetors slurped up to 11,3 l/100 km
(= 1 liter for every 8,8 km = 33.5 km pro USA-gallon = ca 21 mpg). Both
carburetors with their air filter are forced under the tank in such a way, that
for the primary function of this tin-saucer (blechschüssel)
only 17 liters remains. That is sufficient as long as the XZ is not pushed to
the limits. During normal riding an average of 5 or 6 liters is used for 100 km
(1 : 20 up to 1 : 16.6 = 47.5 miles/USAgallon up to 39.4 m/USAg).
An
exhibition model of the XZ engine
The riders were happy also
with the power at lower revs. From 2500 rpm there is power, and one of the
first persons who used the XZ for long distance travel, ventured to compare it
to a Ducati Pantah.
Indeed one can suppose that
the Yamaha designers had a glance to
MOTORRAD-editor Herwig writes 21 March ’83 when the XZ had done 13.000 km:
“Engine accelerates not good, has problems from 100
km/h on, chokes when the throttle is opened. The cycle part is a disaster”
A bit more concise, but just
as clear, are the words of editor Schäfer who used it
for his daily commuter ride, around the 2000 km mark. It was in the cold April
month of ’83: “cold starts are excellent, starts immediately and needs only
choke for a short time. However, when the engine is hot, it starts bad. Riding
position is bad, even for not so large riders…. One sits uncomfortable or too
far back, what makes a good contact with the XZ difficult. The handlebars are
bad, one makes automatically a curved back (nice greeting of the intervertebral disk), cycle parts unstable, small bumps and
potholes cause the XZ to wave in such a way that the pleasure of riding
vanishes. Changes of direction when the bike is leaned-over are dangerous. Bad
surfaces make the motorcycle jump like a mad horse. On good surfaces the XZ is
rather good-natured. The cause of the rather unstable characteristics of the XZ
is the extreme narrow swing arm bearing.
However, not only riders
complain in the logbook on the lacking comfort of the XZ 550. In the first place the
rear passengers were unhappy about the XZ, already after short distances. Too
high footrests and a modern, read: running down, seat, renders the stay on the
back of the XZ a dubious pleasure, that also takes
real long time. Indeed, the riding characteristics of the XZ, with 64
horsepower on paper, leave much to be desired with two persons on the bike. How
few horsepower were really available, turned out at the end of the test when
the XZ was put on a Bosch test-unit. This test-unit
showed that it had 49 horsepower at the clutch and only a ridiculous 43 hp at
the rear wheel. So it is no surprise that the maximum speed with two persons on
the bike was only slightly over 155 km/h (155 kph =
ca 97 mph).
So one third of the power is
lost between specifications on paper and rear wheel. The easy task of the
mechanical parts of the test-XZ resulted in few repairs and in small wear of
parts, such as was demonstrated after the dismantling of the complete XZ. The
gearbox, engine and the cycle parts were nearly all in impeccable condition.
The test-XZ was dismantled after 25.000 km. Caption:
The forks of the gear change mechanism were still impeccable after 25.000 km
(Fig. 1). The housing of the starter clutch was dented (Fig. 2). Both cylinder
heads had heavy deposits (Fig. 3). The valves were hammered-in (Fig. 4) and
must be renewed. A camshaft bearing block is damaged (Fig. 5).
Only one camshaft bearing
cap and the valves show wear. The resulting problems clearly show up in the
compression measurements that, with values of 8,5 and
9 bar, have lower, but more equal, values than at the beginning of this long
distance test. The cause is the strongly hammered-in exhaust valves,
that do not seal any more perfect.
But the XZ’s
low performance level is not caused by this compression loss. The bike had
exactly the same top speed as at the beginning of the test. Surprisingly little
rust was seen on the frame after use during the winter. The quality of
workmanship is a positive point.
The starter worked perfect
during the complete test. That is surprising, as was demonstrated at the
dismantling of the bike. It was rather worn down. The cover of the starter
clutch was dented and had to be renewed.
The oil use over the 25.000 km was negligible. The 4.000 km trip under
heavy use conditions through
The XZ 550 has raised
expectations as a sport-bike. It cannot fulfill these expectations. She was
sent to a battle field by her strategists where she has nothing to do, and as
such, was programmed as a loser.
The XZ 550 is not a
dream-bike, like the Derek woman used as a comparison at the beginning of this
report.
Trouble-free general motorcycle, that is a correct claim for the XZ.
Only, now in August ’83 it
is certainly too late for a new marketing venture in a market that has already
been divided.
Test report by Ulrich Burbach
Translation by XZv2
* In
Postscript by XZv2
There is also a list of all
expenses. You can see that a new R/R was needed, but no stator, so obviously
the stator held out 25.000 km! Surprising in view of the fast
speed two-up holiday trips to
In total 1561 liters of gas
(normal grade) was needed for the 25.000 km. Four rear tires and 3 front tires
were bought. At ca 5000 km and at 10.000 large maintenance
was done, smaller maintenance at 15.000, 18.000 and 23.000 km.