At the time, it seemed like the greatest idea since the
invention of the wheelie: a dual-purpose bike with performance. "It" was
the KL600R, Kawasaki's long-awaited entry in the Open-class dual-purpose
sweepstakes. And when the KL was introduced late last year, it looked to have it
all: a 600cc, single-cylinder, four-stroke engine that not only had four valves
but dual overhead cams; that was not air-cooled but liquid-cooled;
that used not just one engine counterbalancer but two.
Not only that, the
engine's top end had the same profile as the new 900 Ninja's, and the whole
business was carried in a single-shocked, disc-braked chassis that featured a
box-section aluminum rear subframe. And when all of this was combined with the
fact that the KL600R was being built by Kawasaki, the Oriental hot-rod company
that had brought us such legendary pavement-wrinklers as the Mach III Triple,
the Z-l, the GPz series and the fearsome 750 Turbo, there was only one
conclusion to reach: The KL600R is one serious machine that is going to
be the most fire-breathing dual-purpose motorcycle ever built. Period.
Apparently, something got lost in the translation. The KL600R's
performance is, shall we say, a bit off the bull's-eye. And you only need look
as far as our recent road tests of Honda's XL600R and Yamaha's XT600 to see just
how far it is off. Our KL's best run at the dragstrip was 14.28 seconds
with a trap speed of 88.88 mph. That's about half a second and 6 mph slower than
both the Honda and the Yamaha. The Kawasaki's 97-mph top speed is 3 mph below
that of the XT and 6 mph less than the Honda's. A look at top-gear roll-ons is
equally distressing. The KL takes 5 seconds to accelerate from 40 to 60 mph;
Honda 4.3, the Yamaha 4.6. From 60 to 80 mph the the Kawasaki requires a full 7
seconds, while both the Honda and Yamaha need only 5.6, which is almost a second
and a half less. In fact, even Honda's XL350 is quicker in that respect.
From these figures, an educated guesser would say that the
"technologically advanced" Kawasaki is about 5 horsepower down on its
more-conventional competitors.
Just why the Kawasaki is lacking in power is a mystery, even to
the company's U.S. officials, who just shrug their shoulders when asked where
the horsepower went. At an actual 564cc, the KL gives away displacement to the
595cc Yamaha and the 589cc Honda, but the engine seems like it has enough
techno-features to make up for the handicap.
Liquid-cooling, for example, has been associated with
high-performance motorcycles because it provides more-uniform engine cooling,
which allows closer tolerances and, theoretically, a higher state of tune. But
the KL, if anything, seems to have a lower state of tune.
In design, the Kawasaki's cooling system is just like those used
in recent moto-cross engines. There are two small radiators mounted in front of
and just below the gas tank, and the coolant, a recommended 57/43-percent mix of
water and anti-freeze, flows from the rightside-mounted water pump to the
cylinder head. From there, coolant is pumped through a thermostat to the right
radiator, behind which is mounted a small, eight-bladed fan to help out when
things get really hot. The coolant then crosses the frame to the second-stage
radiator and is routed via a rubber hose back to the pump. Black,
cowcatcher-style air shrouds made of plastic direct air through the radiators.
In practice, the bike's cooling system worked nicely. The
instrument-panel temperature-gauge needle usually hovered at the halfway mark,
and the fan cut in only a few times during the KL's 2000-mile, late-spring test.
One drawback to the system is that the rider's legs are warmed by hot air
flowing through the radiators. Not bad on a cool spring night, but stop-and-go
traffic on a humid summer day is another story. We also expected the
liquid-cooling to be more effective as an engine-noise buffer, but the KL made
enough banging and rattling racket that several bystanders gave a quizzical,
is-that-thing-all-right look at the idling Kawasaki.
Water-cooling isn't the only area where the KL's engine differs
from its competition. Both the Honda and the Yamaha have four-valve cylinder
heads that's almost expected of four-strokes these days but their valves are
operated by a single camshaft. The Kawasaki has two cams, chain-driven from the
crankshaft. The use of double overhead camshafts is usually reserved for
high-revving engines, where the lighter valve gear yields less reciprocating
mass compared with a single-cam design. And while it's true that redline on the
Kawasaki is set 1000 rpm higher than it is on the other dual-purpose big-bores,
the twin cams haven't helped the KL close the horsepower gap.
Another difference in this atypical engine is the oiling system.
Most large-displacement dual-purpose and off-road four-stroke Singles use
dry-sump systems. Although this type of oiling requires the use of a separate
oil reservoir—the Yamaha uses a side-mounted oil tank, the Honda a frame-tube
reservoir it allows a lower engine height, which is an important consideration
for inherently top-heavy four-strokes. But the KL600 utilizes a wet-sump oiling
system, mainly because the company's recent streetbikes and its dual-purpose 250
all use wet sumps, and that's the type of oiling system Kawasaki's engineers are
most familiar with. Plus, the feature-packed KL600 already is $50 more expensive
than the Yamaha and $103 higher than the Honda, and a dry-sump system would have
added to the KL's price.
Indeed, but the wet-sump system has added to the KL engine's
height, for the need to carry the oil under the crankshaft has made the
engine taller about one and a half inches taller than the Yamaha's engine, for
example. Surprisingly, the KL doesn't feel any more top-heavy than the Honda or
Yamaha. This despite the extra height of the engine, the high location of the
radiators and a test weight, at 325 pounds, that is seven pounds heavier
than the Yamaha's and 10 pounds up on the Honda's. The KL's engine does,
however, have a distinct advantage over the XL's and XT's in that Kawasaki
fitted the 600 with counterbalances to smooth out the big Single's vibration.
Both the Honda and the Yamaha use single, gear-driven counter-balancers, and
while these systems help quell the shaking, there's enough left to spoil long
highway trips. The Kawasaki, on the other hand, is smoother at cruising speeds,
smoother, even, than some road-only bikes. At an indicated 60 mph (actually 54
mph, the speedometer is hopelessly generous) the footpegs are almost buzz-free
and the handlebar passes only a slight tingle to the rider. As the revs climb
past 5000 rpm, a typical big-Single vibration returns, but the KL600 is
nonetheless the smoothest thumper we've ever ridden.
Next on the things-done-differently list is KACR, pronounced
cacker, which stands for Kawasaki Automatic Compression Release. Almost
every other four-stroke Single sporting an automatic compression release for
easier starting has the device linked by cable to the kickstarter mechanism. The
Kawasaki is different in that the KACR unit is mounted on the exhaust camshaft
and comes into play only at cranking speeds. At those speeds, the centrifugally
operated KACR opens the right exhaust valve one millimeter. This provides enough
decompression to substantially reduce kicking effort. When the engine fires, the
cam speeds up, the KACR retracts and the valve operates normally.
Still, despite all its new-fangled features, including KACR, the
Kawasaki can be as difficult to start as the infamous big Singles of yesteryear.
And just as with those motorcycles, there is a starting drill. If it's done
right, the KL will fire in three kicks or less. Get it wrong and the KL acts
like a two-wheeled Nautilus machine designed to develop leg muscles. The drill:
Move the handlebar-mounted choke lever to the full-on position, do not, under
any circumstances, touch the throttle, push slowly down on the kick start lever
until some resistance is felt (that's the piston coming to top dead center),
keep pushing slowly until the piston is just past TDC (the resistance will go
away), let the kickstarter return to the top of its stroke, think good thoughts
and, while wearing sturdy boots, kick the lever through. The drill worked well
enough that by the end of the KL's test period, our testers were disappointed if
the bike didn't start on the first or second kick.
Once running, the KL wasn't bothered by the stalling problems
that plagued our XL600R or the mid-rpm stumble that persisted on our XT600.
Credit here goes to the 40mm CV carburetor, which uses a flat slide rather than
a standard round one. Kawasaki claims that the flat slide is lighter and takes
up less room than a round slide. Engineers will also tell you that a flat-slide
carb offers better atom-ization of the incoming fuel and, hence, better throttle
response. Certainly, the KL's consistent, if slightly stunted, power
characteristics bear out this claim.
Attached to the carburetor is a large plastic airbox that won no
fans during our test. To get to the air filter, you must remove two screws
holding the right sidepanel, then the panel itself, followed by four more screws
that secure a door to the side of the airbox. The filter a flat, smallish panel
of foam can then be slid out. Our test bike's filter wasn't sealing properly
when we first got the machine, a situation remedied by the application of grease
around the foam's edges. In addition, the airbox itself didn't ward off water
all that well. After 45 minutes of splashing around in a shallow stream— more
severe treatment than most dual-purpose owners will put their bikes through,
admittedly—the air filter was wet enough to choke the engine. Wringing out the
filter had us on the move again, though the KL wasn't very happy about the whole
ordeal, and required a few miles of riding to dry out completely.
That the engine doesn't capitalize on its hi-tech credentials is
a shame, because the rest of the motorcycle works well; in some instances much
better than the competition. The seat, for example, is a good compromise between
the
Honda's, which is too soft, and the Yamaha's, which is too hard.
Together, the seat and the relatively smooth, relaxed power characteristics of
the engine make the Kawasaki's KL the best choice for the dual-purpose owner who
spends most of his riding time on the highway. Regardless of the terrain, all KL
riders will appreciate the gearbox's slick shifting and properly spaced ratios
as well as the bike's clutch, which survived its ordeal by test a lot better
than those on some other dual-purpose bikes we've tested recently.
For riders with a preference for sporting backroads, the big
Kawasaki is an able partner. It's no roadracer, but the standard dual-purpose
traits of light weight (compared to that of most streetbikes) and virtually
unlimited ground clearance allow the KL to negotiate a twisting section of
asphalt with enough speed to embarrass more than a few knees-out riders on
purebred sport machines. The only unsettling component in backroad adventures is
the front disc brake. Though it's not lacking in stopping power, it gives little
feedback to the rider and requires high effort at the lever. During braking
tests, the best results were obtained when our rider pulled the brake lever in
until it hit the handlebar grip. The drum rear brake provided adequate stopping
power and predictable control.
The KL may be able to out-handle some road-only bikes on the
street, but it'll never show its heels to a motocross or enduro bike off-road.
That's to be expected. The KL is a lightweight on the street, but it is a bit
heavy for serious trail riding. And while nine inches of suspension travel will
soak up just about any road obstacle, it gets used up in a hurry when jumping a
325-pound motorcycle off of ledges and hopping it over rocks.
Not that the Kawasaki doesn't account well for itself in
off-road situations. Remember its limitations and the bike will take you almost
anywhere. Just don't expect to get through the rough stuff first with the least
amount of effort when in the company of a real dirt bike.
Credit for the amount of dirt prowess that the KL does have
belongs to the sturdy frame and compliant suspension. In talking with Kawasaki
officials, we learned that the frame was originally designed as an open-cradle
type a la the Yamaha XT Late in the development program, however, bottom
frame tubes were added for increased rigidity. And if the rear of the frame
looks like it was intended for an off-road racer, that's because many of the
accompanying components were. The single rear shock, with adjustable spring
preload and four-way adjustable rebound damping, is from last year's KX500
motocrosser, although the spring is softer and there is no remote oil reservoir.
The Uni-Trak rising-rate rear suspension system attaches the shock to a
beautifully crafted aluminum swing-arm that pivots on needle bearings and
features eccentric chain adjusters. The eccentrics not only allow easy chain
adjustment, but rotating the eccentrics 180 degrees effects slight changes in
ride height (and thus, steering geometry) which can help speed up or slow down
steering response.
The rear frame tubes that support the seat also show off-road
heritage. Made of square-section, extruded aluminum tubing, the whole assembly
attaches to the steel mainframe with four Allen-head bolts. Removable rear frame
sections are popular with motocrossers because they allow easy access to the
rear suspension when it comes time to clean, adjust or replace the shock. Most
KL owners will never have to take off the frame section, but there's no denying
that the nicely welded aluminum tubes do look stylish and probably are lighter
than any steel counterparts.
At the other end of the bike, an air-cap-equipped fork assembly
with 38mm stanchion tubes handles the suspension duties. Kawasaki recommends
zero psi, however, as the best starting point. Like the rear shock, the fork is
light on springing and bottoms easily when the bike is ridden very aggressively
in the dirt. The KL could use slightly stiffer springs front and rear—not enough
to ruin the bike's compliance to small street irregularities, but enough to give
the bike more of a fighting chance in the rough.
Putting things in perspective, the Kawasaki KL600R is a
dual-purpose motorcycle bristling with technological features, but it's
nonetheless out of the horsepower hunt. That isn't as heavy a burden for the KL
to bear as it might at first seem, because in all other aspects the Kawasaki can
hold its own against the other big-bore street/trailers, if not do better.
Still, there's no getting around the fact that the Kawasaki
gives away horsepower to the more established Honda and Yamaha. For the casual
street-and-trail rider, that's not much of a problem. But for riders who like to
pack all the fun they can into their rides, sooner or later the extra five
horsepower is going to be wanted or needed; and getting that power if and when
speed parts become available in the aftermarket is only going to widen the price
gap between the KL and its competition.
Source Cycle World 1984
Any corrections or more information on these motorcycles will be kindly appreciated.