When the FZ750 was introduced in 1985, it created quite a stir. There had
been two-valve engines, three-valve engines and even four-valve engines, but the
radical, race-ready five-valve Genesis design was fresh, beautifully executed
and performed famously on the street and on the track. It brought home the fact
that motorcycle engine technology was leading the entire engineering world—not
even Formula One cars had as many valves as their drivers had fingers. The
valves got all the attention, but the layout of the bike is just as radical.
Fuel is heavy; chassis designers want to get it as low as possible. Upright
cylinders and the traditional bank of carburetors behind them force intake ports
into contortions that slow airflow at high rpm. The solution is to cant the
engine radically forward at about 45 degrees.
This gets the weight of the
cylinders down and forward, where it belongs, and allows the carbs to be mounted
high, with the light but bulky airbox above them. And the fuel can now sink into
the frame where the carbs used to be. It's simple, elegant and, like most other
advancements, it causes observers to wonder why it had never been done before.
But even a breakthrough design is only as good as the competition's next major
model change. The FZ is now the oldest 700/750 sport bike from Japan. Suzuki
followed with the feather-light, oil-cooled production-race-oriented GSXR. Honda
backed up the original 750 Interceptor with the smooth, fast and refined VFR.
And late last year, Kawasaki started selling the 750 Ninja, another slick
combination of arm-ripping acceleration, lancet-sharp handling and real-world
ergonomics.
The FZ was revolutionary—but can it still run head to head with the
hot young punks on the block? Yamaha has its own revolutionary sport 750 this
year, the rare, expensive and exotic FZR. Its Deltabox aluminum frame and
race-ready brakes, wheels and radial tires are exciting, but its over-$6000
price and severely limited availability will take it out of the hands of even
the most rabid street rider. So the FZ700 is now Yamaha's loss-leader sport bike
for the masses. Ogle the FZR on the showroom floor, but put your down payment on
the tariff-beater.
The displacement has been dropped to 697cc by the simple
expedient of destroking the crankshaft; the pistons move 48mm in the 700, 51.6mm
in the 750. The pistons have changed radically; they are much lighter than
before, with almost no skirt area at all. The rings are also narrower and
lighter, and the rods, like those in the new FZR750 and FZR1000, are lighter and
stronger.
Lightened reciprocating parts (Yamaha claims the piston-ring-rod assemblies
are 13 percent slimmer) are often the basis of an all-engine weight-loss
program; with less mass flopping on the crank throws, the crankshaft journals
can be reduced in size, the crank can be made lighter, and the cases that
support the whole mess can be pared down as well. Yamaha hasn't gone that far;
the crank and cases are just as beefy as before; meaning the new 700, with its
trimmed-down bouncing parts, should be even more durable than the nearly
bulletproof 750.
The valve gear, with its three-intake, two-exhaust layout, is unchanged. Tiny
bucket-and-shim lifters, cleverly stacked inside the two-layer head assembly,
act on the valves directly. The hollow camshafts must be removed to adjust the
valves, so Yamaha made sure the process would occur infrequently; the light
valves, sintered metal seats and general high quality of the parts let Yamaha
call for valve adjustment every 27,000 miles.
The previously redundant exhaust system, however, has been cut in half. Like
Suzuki's GSXRs and Yamaha's own FZ600, the new 700 uses a four-into-one system
with a single muffler on the right side. The exhaust timing has also been
juggled to work with the new pipe; lift is the same as before, but the exhaust
cam opens the valves on a new schedule.
Digital electronic ignition is all the rage in Japan these days, and the FZ
has it. There are no moving parts, other than electrons, and the new system
allows designers to adjust timing at as many as 22 separate rpm points, letting
them fine-tune the spark to follow the engine's needs exactly.
The obviously new parts of the 700 are on the outside. The fairing is more
substantial; the upper part is close to the old one but with triangular
contraptions at each forged handlebar to keep airflow off the rider's hands. Air
intakes at the front of the hand fairings duct cold air to the airbox area in a
variation on Yamaha's YEIS intake ducts on the new FZRs. The '85 750 was naked
below the waist; the '86 came with a chin fairing. Now the '87 is completely
clothed, with the engine almost completely covered by wraparound ABS. The
windshield is 50mm (about 2 inches) taller to further separate the rider from
the windblast. The side panels are resculptured, with Ferrari Testarossa-style
cheese graters directing airflow out of the central chassis section. The tank
and seat are unchanged, although the seat seems more comfortable than on
previous FZs.
The chassis remains as it has always been: long, low, rigid and a little
quirky. The frame is steel, but don't sneer—it's the same frame Eddie used last
year to carve 'em up at Daytona, so most riders on street tires should be happy
with its rigidity. The wheelbase is a tourer-like 58.9 inches, and although we
don't know where it came from, there's an extra 0.4 inch (10mm) between the
axles that wasn't there last year, according to the spec sheets. Eddie likened
his racer FZ to a Winnebago last year, but that's in comparison to his 54-inch,
250-pound YZR GP bike. Most of the rest of us find steering moderately quick but
with a propensity to require fairly serious changes in steering input with
changes in braking or throttle. The 700, like its 750 progenitor, wants to stand
up in corners, especially slower ones. Touching the front brake lever increases
the stand-up tendency greatly; the relatively soft fork springing gives the
rider a few milliseconds to adjust his steering as the change occurs, but the
first few applications of brake while leaned over will have most riders bobbling
their lines a bit. It's possible to slam the FZ over with the brake on, but
takes a fairly heroic push on the handgrip to do it.
Moving the throttle around in a corner also affects the line profoundly.
Rolling off the throttle tightens the line, and rolling it on widens the exit.
Our riders found themselves consciously using the throttle to steer instead of
the handlebars be-
cause adjusting the throttle gave smoother, more predictable results. The FZ
just feels as if it wants you to leave the handlebar alone once you're committed
to a corner. The long wheelbase and relatively soft front end encourage the
rider to stay smooth with his steering inputs to avoid disturbing the chassis'
equilibrium.
With the stock Bridgestone Exedras, the 700 shows a propensity to push the
front end when the rider's adrenaline level hits condition red; compared to its
competition in the class, the FZ takes a considerable amount of planning to get
through a corner with equal speed. Replacing the pointy and short-lived front
skin with a more rounded high-performance tire is recommended by experienced FZ
hot shoes.
A couple of the trick features of the FZ750 are gone on the budget-minded
700. The rear shock once had Yamaha's slick, adjustable rebound damping, which
adjusted the rates automatically as the remote preload adjuster was spun. The
new shock is not adjustable, and preload is changed at the bottom with a simple
locking ring. And, alas, the centerstand is gone. The holes are there if you
want to install your own.
The brakes, as always, are excellent; the 267mm front discs and double-action
calipers respond well to a light touch and don't fade until the right rider, on
the right racetrack or downhill canyon, starts to really work them over. The
rear disc may be overkill; it's the same size and caliper style as the front and
can be locked up easily by a rider with an inattentive right foot.
An '85 or '86 FZ750 owner would feel right at home with the revised motor.
Throttle response is a bit quicker due to the reduced mass of the parts flailing
around inside. The FZ has long been known for an excellent spread of power, and
the 700 doesn't seem to have lost much as its displacement has shrunk. Usable
power begins with the tach needle barley off the pegs and builds to a raspy,
impatient crescendo as it winds to its 11,000-rpm redline. The powerband is wide
but progressive, and the FZ has a way of always delivering a little more power
than you expected with a given throttle opening, making it a very exciting,
satisfying engine to work with on a mountain road.
Our FZ700 was run at Baylands Raceway, where excellent traction tends to give
bikes a slight edge over those run at Los Angeles County Raceway, our usual
high-desert test venue, even after the quarter-mile runs have been corrected for
weather conditions. The 750s from the Japanese have consistently run neck and
neck at the strip—the differences are so slight in performance, none of the
machines can be called a clear winner. With the Honda and the Yamaha now 700s,
we would expect them to run a bit behind the Suzuki and the Kawasaki, but we'll
have to test them all on the same day and at the same track to know for sure.
Our 700 ran a best quarter of 11.40 seconds at 117.2 mph. With the weather
factored in, that translates to a 11.37 at 117.5, just a little faster than the
Honda VFR700 (at 11.70 and 114.8) and slightly weaker than the industry-wide 11
seconds and small change runs made by the 750s. The 700 suffered in the top-gear
roll-on compared to its bigger, older brother. It got to 75.8 mph 200 yards
after the throttle was popped open at 50 mph, which put it 3.3 mph slower than
the '85 FZ and 3.4 faster than its closest competition in displacement, market
position and price—the'86 Honda VFR700.
The FZ's street manners are admirable but not perfect. Five-valve Yamahas
have always had nOtchy throttle response right off idle; the FZ750, 700 Fazer
and even the long-departed Maxim X tended to lurch a bit as the throttle was
pulled off the stops in a slow corner. The FZ head may be right at the limit of
valve area to get acceptable air velocity at low speeds; it seems the Mikunis
are having a hard time mixing the air and fuel properly at small throttle
openings and still getting past the EPA's pipe sniffers with passing grades. The
FZ700 still has a glitch here, but it didn't seem as bad as on previous
models—perhaps the new finely honed digital ignition is compensating for the
minor inadequacy of the carburetion.
The solidly mounted motor has no counterbalancing, and a small amount of
buzziness finds its way to the rider. Our machine tingled in the bars and the
tank at 4500 rpm, which happens to be an indicated 60 mph in sixth, right where
most riders will ride most of the time on an open highway. The vibes are
noticeable but not particularly annoying, and one always has the option of
downshifting to fifth to move the buzz point away from a given road speed. The
700 has a new cushion ring on the clutch to give smoother engagement; we didn't
notice a significant difference in feel or in drag-strip performance. The
six-speed trans is a trouble-free shifter but still doesn't haveihe light touch
and silky feel of a good Suzuki or Kawasaki gearbox.
The FZ is aging gracefully. It has kept up with the times as its competition
has evolved and yet retains the character that stood the original '85 model
apart from the mainstream of engine and chassis design. With its new bodywork
and paint, it's a much flashier package than before, and the combination of
moderately comfortable riding position, bulletproof and soul-stirring motor and
fully competent handling make it a viable choice in the marketplace. Its main
competition, the Honda VFR700, is $50 cheaper, a year newer in design, a bit
more comfortable and a bit easier to ride—but that won't stop a
dyed-in-the-leather Yamaha partisan from opting for the closest he can get to an
Eddie-at-Daytona replica. 11
Source MOTORCYCLIST/APRIL 1987 71