Before there were Japanese style-cruisers or power-cruisers or
half-ton touring Titans or repli-racers big and small, there were only
standards. From all corners of Japan they came, stacking four cylinders across
twin-shock frames. Standards were town and counUy stormers, their
bailiwick wide and deep, their differences subtle. Year after year, new models
brought higher levels of function—engine performance, covr\for[,
convenience, solid handling. Yet success killed the standards. They were
destined to vanish; their greatest sin was being common.
Americans turned to cruisers for something different—a certain
look, sound, feel, mystique— and the standard fell victim to this
tyranny of intangibles. Comfort? Convenience? Versatility? Although
today's cruisers are slowly heading back to more sensible ergonomics, those
that crumple riders into unnatural positions still outnumber those that don't.
Motorcycling also has repli-rac-ers that sacrifice convenience and versatility
for cutting-edge performance as well as full-boat tourers that continue to
bulge toward motel proportions. Contemporary motorcycling has everything, it
seems, but wide-spectrum motorcycles, and that fact has not escaped Kawasaki.
Unlike specialized motorcycles as limited as bit actors,
Kawasaki's ZL600 is an all-purpose player covering a broad, majestic stage:
boulevard leads to open highway and open highway to mountain pass.
The ZL600's styling is neostandard, despite its fatso
150/80-15 rear tire, and its ergonomics ride the middle of the road. Its
appeal sinks in at dusk, after you've trolled through town, after you've
ridden for a hundred miles in comfort on the freeway, after you've reveled in
the immediacy of its power delivery, after you've experienced the ease with
which it hustles down knotted mountain roads, after you've ridden everywhere
that roadways go and realized the ZL never once felt out of place.
Mere fledglings will sense the ZL's sporting character: it
feels light, stable, reassuring in a way that makes average riders push harder
in the tight stuff than they would on the Ninja, and feel more comfortable
doing it. An expert-caliber rider wheel the ZL600 as quickly as the
high-strung Ninja 600 on all but the fastest swervery.
And power? The ZL600 has more bottom end than the 600 Ninja,
pulling easily away during 45-70-mph roll-ons in fourth, fifth and sixth
gears. The Ninja, with more top end and more slippery aerodynamics, plays its
advantage only at the end of the drag strip. Both bikes turn ETs within a
tenth of each other; the Ninja's terminal speed is nearly four mph faster.
Like the big Eliminator introduced last year, the ZL600
adheres to the basic Ninja engine formula—six-speed gearbox, liquid-cooled,
oversquare cylinders with 16 valves—but features shaft drive and carefully
orchestrated changes to flatten the Ninja's high-rise power curve. The ZL600
is more aggressive down low, its carburetion crisper and more immediate than
that of its exotic repli-racer cousin. Though big and small ZLs share the same
powerband-reshaping philosophy, Ka-' wasaki engineers achieved more impressive
results with the 600.
In the ZL600, Kawasaki engineers reshaped the powerband
without cracking a single engine gasket. The 900 Eliminator was recammed to
spread power, but the 600 shares cam specifications—duration, lift, and valve
overlap—with the 600 Ninja. Where the 900 uses a large resonance chamber to
manage exhaust pulses for stronger mid-range, the 600 employs only a narrow
crossover tube. The exhaust system, together with the smaller carbs and their
airbox, accounts for the re-contoured powerband.
Ninjas make peak horsepower upstairs. Large valves and big
carbs work well at high engine speeds; hence the 600 Ninja's outsized 32mm
units. But big-throated carburetors, especially round-slide mixers, meter fuel
poorly at low rpm. In the 600 Ninja, Kawasaki engineers used the flat/round
slide carb design first seen on the big Ninja to promote better fuel
atomization during part-throttle openings. The ZL600 benefits first from the
same carburetor technology and then from its smaller, 30mm Keihins. The
decrease in venturi size increases air velocity at lower engine speeds,
promoting more complete fuel atomization, better fuel metering, crisper
response, and, ultimately, more usable power.
On the dyno the ZL spots the Ninja top-side power, as well as
lacking a decisive advantaged downstairs with a peak output of 57.24, the
ZL600 lags five horsepower behind the Ninja. Past its 10,000-rpm peak, the ZL
chokes as the Ninja soars. But the ZL starts out as much as two horsepower
stronger than the Ninja, and from there it's a see-saw battle. The ZL is up at
4500, the Ninja at 5000; ZL again at 5500 and the Ninja at 6000; at 6500, the
ZL edges ahead, reaching its biggest power advantage—2.4 horsepower—by 7000
The ZL's low- and mid-range dyno numbers don't reflect its
roll-on advantage on the road. Why does the ZL squirt away from the Ninja in
roll-on contests and match its quarter-mile quickness?
Two reasons: First, dyno numbers are generated with engines
running at a constant throttle setting—wide open. But roll-on tests measure
acceleration in a real-world environment where engines accelerate from part-
to full-throttle. In such conditions, the ZL's smaller mixers provide superior
response, accounting for mucht)f its roll-on advantage. Second, though the two
600s share transmission and primary gear ratios, a different rear tire and
final drive gearing let the ZL engine spin significantly faster than the
Ninja: At 60 mph, the ZL is taching 5102 rpm, the Ninja 4756 rpm.
Lower overall gearing pushes the ZL further up its power curve
than the Ninja at the same ground speed. The combination of lower overall
gearing and crisp carburetion is hard to beat. With a 0-60-mph time of 3.36
seconds (the Ninja takes 3.52 seconds), the ZL makes up what it lacks in peak
power with a hard launch off the line. In our 45-70-mph roll-on tests, the
ZL600 begins and ends its runs anywhere from two to four horsepower stronger
than the Ninja. On the road the ZL has a solid horsepower advantage over the
Ninja up to 9500 rpm. By the time the Ninja hits 9000 rpm, the ZL is already a
quarter-scale dwarf on the horizon.
The ZL picked up its parts from places beyond the Ninja bin.
Since the KZ/GPz/Ninja/ZL belong to the same engine family, adapting the shaft
drive was a bolt-on proposition. The entire shaft-drive unit—bevel gears front
and rear, drive shaft, and transfer case— were grafted from the KZ550 LTD, now
discontinued. The forward bevel gears, however, are now supported by roller
bearings rather than the KZ's tapered bearings to cut mechanical losses. Like
the big Eliminator, the 600 also acquired a two-piece clutch housing that
provides limited slip during high-speed deceleration. The new clutch combats
rear-wheel hop sometimes associated with shaft-driven machines.
The ZL's chassis, like the big Eliminator's, is long and low,
and ZLs big and small use the same basic frame layout, with one significant
difference. The 900's frame places the engine's left and right cylinders
outboard of the double downtubes in conventional fashion, while the 600's
frame positions all four cylinders inside. Why? The ZL600's engine is so
narrow, its cylinders so tightly packed together, there just wasn't room
between the header pipes for frame rails. So the 600 got outboard downtubes,
which Kawasaki engineers exploited to achieve more acute trian-gulation and
Beyond its unorthodox downtube design, the ZL's chassis is
simple, low tech, and effective. Example: The ZL uses an 18-inch front wheel
with a single disc brake, and a 37mm fork void of anti-dive plumbing. The ZL
has two degrees more steering-head angle, and, at 61 inches between axles, its
wheel-base outdistances the Ninja's by nearly half a foot.
ZL weight is carried low: the engine sits two inches deeper in
the frame than the Ninja's, and a 28-inch seat height positions the rider two
inches closer to the ground. A narrower front tire, and the forceful leverage
of a higher, wider handlebar helps the ZL through directional changes. This
low center of gravity and high handlebar explain some of the ZL's light, agile
handling. Though it weighs only ten pounds less, the ZL makes the Ninja feel
chunky-large in fast transitions, and it steers quicker and with less effort
than the 16-inch-wheeled ZX. Furthermore, the ZL's suspension
provides superior ride quality to that of the stiff-legged
Ninja. The larger, more powerful Eliminator 900 must use stiff-er spring and
damping rates to control its shaft reaction; however, Kawasaki engineers can
limit pogo-motion in the ZL's shaft drive with light, compliant springs and
softer valving. They have, and, set up softly, the ZL delivers a cushier
freeway ride than the big 900 Eliminator and both Ninjas. The ZL's twin shocks
also offer, through 5 position rebound damping and preload settings, a much
broader compliance range. Preload adjustment is difficult, however. Twisting a
screwdriver stuffed into the spring collar is a crude method of adjustment in
this age of pneumatic shocks, and the ZL's lack of a centerstand further
complicates the process.
But on fast backroads, the hassle pays off. With rear preload
set to full • stiff, and six to eight psi pumped through the fork's separate
nozzles, you can ride the ZL at about 85 percent of a white-knuckle pace and
still enjoy the greenery. Though some driveline lash is present, the shaft
doesn't hamper speedy progress, and the Dunlop skins stick well.
That last 15 percent, however, reaches into the ZL's twilight
zone. The single-disc front brake and drum rear offer good response and
require only light effort, but they don't provide enough stopping power during
highspeed running. While the ZL can accelerate harder, corner to corner, than
the Ninja, its sheer speed gets the best of its braking components. In slow
and medium fast turns, the ZL has enough cornering clearance to joust with the
Ninja, but push the ZL hard in faster sweepers, and its grinding footpegs
trigger a sensory red alert.
Comfort, convenience, versatility, the watchwords of the old
standards, clearly apply to Eliminators big and small. The 900 Eliminator is
miles ahead of most big cruisers for versatility and sportiness, but its low
bars and thin seat are concessions to drag-bike styling. The ZL600 is much
less an "image" motorcycle than the 900 Eliminator and has a wider usefulness:
Its handlebar is higher, its seat wider, flatter, plusher, and its footpegs
As Kawasaki moves toward wide-spectrum motorcycles, the
profile of such new standards as the ZL600 contrasts in so many ways with
"old" ones. The seat skims the ground seemingly because so many riders today
identify their ability to flat-foot at stoplights with comfort and convenience
and safety. Still, old concerns live on, too: for many enthusiasts, shaft
drive and smooth, rubber-mounted powerplants are likewise part of any
general-duty motorcycle. The ZL600's broad-ranged capability
doesn't come cheap: at $3499, the ZL600 costs as much as the
high-tech Ninja. But the ZL600 is a Do-Everything machine that ties the day's
travel into a seamless ribbon of asphalt. To some riders, that's what
motorcycling is all about.