Kawasaki KDX 175
Air cooled, two stroke, single cylinder.
Bore x Stroke
20.1 hp @ 9000 rpm
2.2 kg-m @ 8000 rpm
I'm about to attempt the impossible. I'm about to try to
convince you that a motorcycle can be well, that it can be magic. And I'm
highly optimistic about my chances for success.
You see, the motorcycle I'm referring to is Kawasaki's KDX175 enduro. And
as you are about to read, it routinely works some pretty impressive miracles
in the dirt. It lets—maybe it even makes—beginners ride like experts and
experts ride like beings from some planet where everyone is Dick Burleson.
Now, if that's not magic, what is it?
Whatever it is, the KDX175 oozes it from every nook and cranny. Take my
word for it. Because after 300 miles in AMA national championship enduros
and nearly 500 additional miles of WFO test riding on two of them, I know.
I've tried my damndest to break them, to fall off of them and to make a fool
of myself on them, but so far I haven't had much success. Matter of fact,
these 175cc Uni-Traks are so good that people around here think that I
actually know what I'm doing on an enduro bike. In that respect, riding a
KDX175 has done more for my image than a personal press agent.
You might have read high praise for this motorcycle before, probably in
tests of the original model earlier in the year. If so, you might be
surprised to learn that the '81 version is even better. Not so you'd notice
at first glance, yet Kawasaki apparently found a way to dip the new KDX into
that special magic potion one more time, for it is, without question, a
slightly better motorcycle in virtually every way.
Take the engine, for example, a 173cc reed-valve two-stroke that's been
conspicuously improved with just a few inconspicuous refinements. Like the
window that's now machined into the intake skirt of the piston, extending
the effective open duration of the intake port and the booster transfer port
without requiring any change in their actual dimensions. Translation: better
performance from the middle of the rpm range upward. Additionally, the fat
center section of the exhaust pipe has been enlarged in diameter to increase
its interior volume. That also nets more power in the top half of the rpm
scale. And although the compression ratio remains unchanged at 7.6:1, the
squish band in the cylinder head is reshaped to improve combustion
characteristics at all rpm.
What this means out on the trail is that anyone who liked last year's
engine will absolutely love this year's. Not that the original motor drew
much criticism; most people were amazed at how much power the "little" 175
produced at any and all rpm. It was just short of a trials motor at very low
revs, typically enduro-torquey in the midrange and right in Motocross City
on the top end. Yet Kawasaki claims the '81 engine has three more peak
horsepower; and the fact that the new peak is at 9000 rpm, 500 revs lower
than last year, is your first clue that the rest of the rpm range hasn't
suffered because of that increase. The truth is, there's a noticeable
improvement in responsiveness at medium rpm and slightly more crisp running
at low revs.
I learned first-hand about the wonderfulness of those improvements when,
after having logged hundreds of miles aboard a 1980 KDX175, I debuted an '81
in the Jack Pine National enduro. Time after time in that demanding 200-mile
event, the powerful-but-tractable engine pulled me out of potential trouble
when I made a riding mistake. Sometimes it lugged down to ridiculously low
rpm like a good 250 when brain-fade made me use the wrong gear on a steep
uphill; other times it continued to pull effectively at what sounded like
nine million rpm when my flailing feet couldn't even find the footpegs, let
alone the gearshift. No matter how unreasonable my request, the engine was
willing to comply. Sure, the 1980 KDX had been exceptionally forgiving,
power-wise, but the new engine has two-stroke compassion down to a fine art.
Don't, however, credit all of that to improvements inside of the engine;
some minor changes in exterior systems, such as the carburetor jetting and
the air filter, have done their part to boost the get-up and-go. The
filter's cake-shaped foam element now offers more usable filtering area,
even though it's more squat than before. The shortness keeps the circular
part of the element from pressing against the inside of the left sidepanel,
thus adding that area to the available filtering surface. And while the
increase might not be discernible when the foam is clean and freshly oiled,
the added breathing is readily apparent in the way the engine continues to
pump out good high-rpm power when the element is wearing 100 miles of enduro
That broadened power curve also has effectively remedied one more flaw in
the '80-model KDX: a sizable ratio gap between second and third gears. Last
year's engine sometimes 'had trouble spanning that gap in heavy mud or up
certain hills; but the wider powerband on the '81 usually handles it with
ease, even though all of the ratios are identical to last year's. And if you
do reach a point where one gear is a bit too low and the other a tad too
high, you generally can urge the KDX up into a stronger segment of its
powerband by slipping the clutch—in the taller of the two gears, of
course—to gather speed. The most amazing thing is that the clutch accepts
mile after mile of that kind of abuse without a whimper. I deliberately (and
needlessly) used that tactic on just about every one of the many uphills in
the Oregon National aboard a 1980 KDX, but the clutch adjustment didn't
fluctuate even one millimeter all day.
Indeed, that 125-mile enduro was one I'll never forget, although for
reasons having nothing to do with clutch free play. For one thing, while
several hundred of us were following little red arrows through the Oregon
woods, Mt. St. Helens was blowing her stack for the first time just right
down the road. Nothing like a volcanic eruption to commemorate your first
enduro in more than eight years. But as awesome as that spectacle was, the
KDX175 showed me something almost as impressive that day. It showed me that
all of this business about 175s being too small for big people to ride
competitively is pure bull. By mid-event I had lost over 40 minutes in two
massive bottlenecks, and yet—at six-foot-one and over 200 pounds at the
time—I was able to get back on schedule and zero the last three checks. Not
because I'm one of those Burleson-clone riders. Not because I cheated or cut
the course. But because the motorcycle I rode that day was, as I said
I hear some scoffing and snickering out there. Meaning that, obviously,
you've never ridden a KDX175. If you had, you'd know what I'm talking about.
You'd know that this innocuous-looking little Kawasaki is one of the
finest-handling and most-forgiving enduro bikes ever to leave its knobprint
in the woods. So much so that you or I or virtually anyone can get seriously
and outrageously berserk on one and live to brag about it. And that's why I
was able to make up so much time in Oregon. In fact, the worst thing about
my maniacal ride on the KDX that day was that I couldn't stand at the side
of the trail and admire myself while I was getting away with such
uncharacteristic craziness. Like I said, it's a magical motorcycle.
There are, of course, numerous reasons why. One is that the KDX has an
unusually long wheelbase that helps give it the straight-line stability of a
Greyhound Scenicruiser. That's mostly because the rear ends of long
motorcycles tend to do things slowly—things such as skitter and sidehop.
Better yet, the KDX does them not at all. Furthermore, the bike is
comparatively front-heavy; and while that, in conjunction with the long
wheelbase, makes wheelies more difficult, it also discourages the front
wheel from being easily deflected off-course.
Not that the KDX can't react in a hurry; it most assuredly can, for the
steering geometry is very quick and the center of gravity—due, in part, to
the physics of the Uni-Trak rear suspension—is relatively low. So although
the KDX is stubbornly prone to going in a straight line when acted upon by
outside forces, it will change direction immediately when ordered by the
I experienced the bike's entire range of handling versatility in the Jack
Pine, where one minute the drill was to zig-zag between closely spaced trees
in low gear, and the next it was sandy whoop-dee-doos at the top of fourth
and fifth gear. These examples represent the extremes of the enduro-handling
spectrum, yet the KDX dealt with both conditions exceptionally well. When
the situation called for full-lock steering, the bike seemed as though it
had been specifically designed for it. But it also felt ideally suited for
high-speed rough-riding, for it absolutely refused to get sideways or out of
shape on the cobbiest and fastest of trails.
Not to be overlooked, though, is the contribution the suspension makes to
the KDX's good trail manners. Basically, things in the leading-axle fork and
unreservoired-shock department are almost the same as last year, but there
are some improvements. The fork, for instance, is now fitted with air caps,
and while everything else about it is unchanged, the air-assist allows a
greater range of tunability to suit various riding conditions and styles.
The Uni-Trak shock, too, offers the same rates of springing and
non-adjustable damping as the original KDX175, but there's a new shock body
and single-rate spring that are lighter in weight. Lighter and stronger also
is Kawasaki's description of the bike's imA "torque arms," as they're
called, the vertical struts that connect the steel swingarm to the beefy
rocker arm beneath the seat.
Despite the improvements, I was able to bottom the rear end of both bikes
on some of the more horrendous whoops and bumps, even after I had starved
myself down to 185pounds. That bottoming was for a reason, though, since the
rear spring rate was selected to accomodate average size 175-class
riders—those between about 125 and 165pounds would be my guess. Otherwise,
the rear ends on both bikes behaved impeccably on all types of terrain,
ranging from the stutter of little chops to the slam of giant moguls. My
sole displeasure with the 1980 front suspension, too, was its tendency to
bottom on occasion; but pumping about four to eight psi of air into the
'81-model's tubes left me with nothing to snivel about, fork-wise.
The resultant ride, therefore, is plush, but I do have one complaint
about the bike's overall comfort: The distance between the handgrips and the
footpegs is too short. That's easy to understand, since the KDX175 is,
essentially an overbored KX125 motocrosser. Today's motocross machines have
very short gas tanks and extreme forward riding positions to keep the
rider's weight on the front wheel for better steering; and that situation is
further complicated on 125cc MXers by the fact that the average rider in
that class is quite small. And so my long-limbed body is never completely at
ease when it's up on the pegs, especially when going up steep hills. I have
to devote a lot of energy to just hanging on that would be better used to
steer the motorcycle. If you're five-foot-eight or less, though, forget
everything I just said.
Truthfully, the stand-up position is my biggest gripe about the new
KDX175. Oh, I could whine about how the long torque arm on the full-floating
rear brake is vulnerable to damage or that the brake itself is a bit too
touchy. I could point out that the brakepedal ought to have a folding tip
like the gearshift's. And if I wanted to pick a few ISDT-caliber nits I
could note that the KDX's wheels aren't exactly of the quick-change variety.
But when I weigh the importance of these few items against the utter
competence of the bike's overall performance profile, I haven't got the
nerve to really complain about them.
Besides, it's not as though Kawasaki hasn't made an honest attempt to
improve the KDX. To help extend chain life, for instance, there's now a
plastic chain and on the swingarm to keep the knobs from slinging dirt on
the No. 520 DID. And to prevent the shift lever from being sawed in two when
the chain does develop excess slack, the lever has been reshaped for more
clearance where it passes under the chain. There's also a wider plastic skid
late a longer and wider rear fender, and even a toolbag behind the seat—not
a particularly good bag, but better than no bag at all. And Kawasaki even
found a way to keep the stickers from peeling off of the plastic gas tank.
If those improvements seem trifling to you, if things like windows in
pistons and shorter filter elements and stickers that stay stuck leave you
with the impression that the 1981 KDX175 isn't much better than the 1980
model, you're right; it isn't. But that's not a put-down of the new bike;
it's a tribute to the intelligent design of the original. Which proves that
if it's done right in the first place, it's hard to improve the second time
Make no mistake, then: Kawasaki did it right the first time. That's why
the KDX was and is magic. That's why in more than 450 consecutive miles on
them, including both National enduros, I didn't fall down once. And believe
me, I do fall down. A lot, at times. But aside from when I laid the bike on
its side once to help another rider, the handgrips never touched the ground.
And with me riding, that's magic.
In all fairness I have to admit that "magic" almost is a cop-out in this
case, a word that describes what the bike does, not what it is. But there's
another single word description that tells you everything you need to know
about this motorcycle. When you consider all of the things the KDX175 can do
how well it does them and the incredibly wide range of riders for whom it
can do them when you take into account all of the offbike factors such as
price and reliability and the like, the picture—in my mind, at least-is
crystal clear: The KDX175 is the best all-around enduro motorcycle built.
And not just at the present time.
Little bikes are for kids as far as I can see. And
anything less than a quarter-liter is usually less than enough for me.
Normally, I wouldn't even seriously consider a 175 big enough for my
190-pound frame, so imagine my surprise at liking the KDX. From the first
day in the workshop when I threw a leg over the tall saddle I felt at home.
The bike was light and manageable, but somehow it didn't feel at all like a
kids' machine. The first ride was just as impressive. This was not kids'
stuff but an adult toy that dragged me everywhere I wanted too. From the
steepest hill to the tightest trail I enjoyed a second childhood.
So much pleasure could not come from a single source. Neither the frame
nor the motor alone would have been enough to convince a grownup like me
that 175s are not solely for kids. The KDX convinced me with a perfectly
balanced package. The engine pulls like no 175 I have ever ridden, and the
clutch will absorb just about any abuse. Better still, the suspension will
not pass along any abuse to the rider. It doesn't even give cause for
concern, because at any speed the KDX is stable. Even in the woods it is
After a few days of hard riding I am prepared to admit that there is some
measure of the child in each of us. And the bit inside me wants a
It's easy for me to be contemptuous of 175cc enduro bikes. I know they
offer a combination of light weight and full-size power that should make
them the right choice for 90percent of all enduro riders. But as much as I
acknowledge the wisdom of the concept, the execution always has bothered me.
Basically, I get tired of keeping track of a scaled-up 125 motocrosser on
the trail. Every chipmunk dropping deflects the front wheel, so I'm weaving
through the woods when it's not necessary. And the powerband is so narrow
that the shifting required for a 50-mile loop leaves me bleeding from the
So my appreciation for the KDX175 doesn't rest on its resemblance to
other 175s. Instead, I'd choose this bike because it deals with rugged
terrain with the same unflappable cool as a Husky 250WR. It's got a
full-size chassis that lets me ride the shortest distance between two
checkpoints. Meanwhile, the engine spins out that perfect combination of
low-end thrust and top end horsepower that Yamaha has sought without success
for three years.
Sure, I realize that the KDX is a great 175cc enduro bike. It even says
175 right on the sidecovers. But in its heart, this bike knows it's a 250.
And when you come right down to it, I do, too.—Michael Jordan