Winston Churchill may not havf known Not that the H600 was a total much about
motorcycles, but he was a master was just about unbeatable in production-class
roadracing. at motivating people. Once, for example, to It's just that in the
more important competition to get from rally his fellow Englishmen during the
early, bleak days of World War II, he told them that they could "win the world
Forty-six years later, Yamaha's new FZ600 is tangible, two-wheeled proof that
Churchill was right, that through sacrifice comes victory. The FZ's world is
that of the no-compromise sportbike; and after years of coming up second- or
third-best in the mid-displacement sportbike wars, Yamaha's entry finally has
what it needs to slam the door on its competitors. That transformation involved
sacrificing some of the all-around flexibility possessed by the FZ's
predecessor, the F.I600, in order to make this new machine the finest pure
sportbike in the class.
Not that the FJ600 was a total loser. In fact, that the bike was just
about unbeatable in production-class roadracing. It's just that in the more
important competition to get from the dealer's showroom to the customer's
garage, the FJ ran into twin buzzsaws from Kawasaki and Honda. Both the Ninja
600 and the Interceptor 500 looked racier than the more-mainstream FJ600, and
Yamaha found itself with a good middleweight sportbike that was setting records
the racetrack but not on the sales charts.
Obviously, something needed to be done. But the catch phrase at Yamaha for
1986 is "Evolution, not revolution,' meaning that a new-from-the-tires-up bike
was out of the question. That didn't prove to be a monumental stumbling block,
however, because Yamaha already had the components in-house that it would need
to build a world-beating, 600-class sportbike. The powerplant for the new bike,
for example, would come right from the FJ600-although in a marketplace loaded
with liquid-cooled engines and combustion chambers stuffed full of valves, the
FJ's motor isn't exactly a technological wonder. The air-cooled, eight-valve
inline-Four has been around since 1980, when it first appeared as a 400 for the
Japanese home market. America got its first look at the engine in 1981, mounted
in the Seca 550 sportbike.
So in all aspects, the FZ's engine is quite conventional. Double overhead
camshafts are driven by a roller chain running through the middle of the
cylinder casting. Valve clearances are adjusted via shims inside of buckets atop
the valve stems. Two-piece connecting rods bolt around a crankshaft that turns
in plain bearings. And in a move that was innovative five years ago but hardly
earth-shaking now, the generator is mounted behind the cylinders, above the
six-speed gearbox, allowing an engine width of just 16 inches.
Despite its rather unimpressive specifications, though, the 598cc engine has
proven itself capable of propelling any chassis into which it has been wedged up
to and often beyond class performance standards. But with the FZ600, it's the
chassis that gives the bike its leg-up on the competition. For two years, this
particular collection of rectangular steel tubes has been tearing up the
backroads of Japan in near-legendary fashion, powered by a liquid-cooled 400
Four. And because the 600 engine is essentially just a bored-and-stroked 400, it
was a simple matter to combine the best parts of FZ400R and FJ600 to come up
with the FZ600.
That combination almost assured sportbike success, but it also forced the
aforementioned sacrifices. For one, the FZ, thanks to its 400 heritage, is a
small motorcycle, with a wheelbase that is almost two inches shorter than the
FJ600's. Combine this with hiked-up footpegs and low-mounted handlebars, and
you've got a motorcycle that painfully forces its rider to take straightline
miles at legal speeds in small doses. Not helping matters at all is the thinly
padded seat, guaranteed to make gas stops looked-forward-to events. But at least
the rider's seat is better than the laughably under-padded vinyl rectangle that
FZ600 passengers are required to perch atop.
Also adding to the sacrifices is a rear suspension that has been calibrated
more for race-replica leaning than for smooth negotiation of city streets and
expansion-joint-infested highways. Thankfully, the air-adjustable front
suspension is wonderfully supple, responding to even the smallest bump or ripple
in the asphalt.
Ridden at 55 mph for an extended amount of time, the FZ not only inflicts its
rider with numb-butt, aching wrists and kinked knees, but also tingling hands
and feet, for there is an annoying amount of vibration at that speed, in spite
of rubber mounts at the engine's front attachment points. To be fair to the FZ,
Yamaha's mid-displacement Fours have always been buzzy, and at least with this
latest incarnation, the vibration diminshes dramatically as speeds get into the
real-world realm of 65 to 75 mph. What vibration remains is far, far less than
on the FJ600.
If the previous list of sacrifices seems too much for a bike to be saddled
with, think again. Open-road complaints about the FZ are simply blown away after
the first freeway off-ramp. When the asphalt starts to twist and turn, the bike
comes into its own, and suddenly engine vibration goes unnoticed, the cramped
riding position is transformed into the perfect backroad attack stance, and a
harsh rear suspension becomes just right for those hard-left, hard-right
maneuvers. In other words, sacrifices in normal riding turn out to be assets
when the FZ is pressed to its limits.
And with this bike, those limits are high indeed. A trip down a familiar
backroad on the Yamaha is an eye-opening experience. Usual braking points have
to be revised or done away with altogether, and cornering speeds increase by
impressive amounts. But best of all, the FZ accomplishes this without any added
drama: It is an absurdly easy motorcycle to ride ridiculously quickly.
Due to its rigid frame, taught suspension and low, light weight - the FZ is
20 pounds lighter than the FJ600 and a whopping 33 pounds under a Ninja 600 the
Yamaha is endowed with almost magical handling. Everyone who rode the bike, from
backroad novice to national-class roadracer, came back with tales of light,
pinpoint-accurate steering, of being able to change cornering lines at will, of
going faster on a particular section of road than they had ever gone before.
Because the FZ600 easily devoured any backroad dish we could serve up, we
took the bike to Willow Springs Raceway to see if faults would show up at race
speeds. For the most part, none did. With the rear shock set on its lowest
preload setting, the footpegs would occasionally scrape the tarmac. And the
front fork, despite its variable damping valve that restricts oil flow during
compression, still dove excessively when the brakes were applied hard. Setting
the shock to its highest preload and adding five psi of air to the fork helped
both problems. Our resident go-fast guy felt that the rear shock could use more
compression damping and wanted heavier-rate springs in the fork, but he still
felt the FZ would be a better choice for road-racing than the FJ600. That's
about the highest praise possible, since he already owns the box-stock 600cc
track record at Willow Springs - on an FJ600.
If there was one aspect of the FZ's performance that left us wanting more, it
was the engine's output. At a claimed 68 horsepower, the new bike is down four
bhp from the FJ600. although that deficiency is well masked by the bike's light
weight and slippery aerodynamics. Yamaha says the FZ has been detuned slightly
through 2mm smaller carburetors - to help improve the engine's mid-range
performance; but the truth is that the frame's tight dimensions meant that
Yamaha had to make sacrifices with both carburetor size and airbox
volume. There simply wasn't enough room to fit the kind of free-breathing intake
system the engineers would have preferred.
Luckily, the bike's drivability hasn't suffered. After getting past a
none-too-strong low-end, the engine pulls cleanly and steadily to its 10,500-rpm
redline. There isn't really a point in the powerband where things explode, but
keeping the revs above 8000 is the best way to make time.
Albeit slight, the FZ600's horsepower deficit is the only chink in its armor.
And having just announced a brand-new 400cc engine patterned after the FZ750
powerplant, Yamaha may be a simple bore-and-stroke job away from being able to
shore up that part of the FZ600's performance envelope. Of course, with a new
Honda 600 Interceptor almost certain next year, as well as a Suzuki GSX-R600 and
perhaps even a revised Kawasaki Ninja 600, the FZ may need all the help it can
get in 1987.
For now, though, on the strength of its marvelous chassis, the FZ600 is just
about unbeatable. To borrow from Winston Churchill again, in the
mid-displacement sport-bike battle, this just may be Yamaha's "finest hour."