The Kawasaki ZX-12R’s 16-valve, DOHC, 1199cc inline-four
engine produces ample horsepower at all rpm range, and includes
a Nippondenso electronic fuel-injection system to smooth its
power delivery. The ZX-12R system utilizes 46mm throttle bodies
with injector tips spraying fuel directly at the intake valves,
however, sudden changes in throttle opening can sometimes cause
hesitation and inconsistent throttle response. The sub throttles
are placed high in the intake tract and are controlled by the
electronic Engine Control Unit (ECU), which automatically adjusts
air intake to more precisely match engine demand. The result
is a smooth flow of power at all throttle positions, similar
to that of constant velocity carburetor designs, with the efficiency
of modern fuel injection.
Compact
stick-style ignition coils help generate the electrical current
to fire the twin-electrode, long-lasting platinum spark plugs.
Burned gasses are expelled through a four-into-two-into-one
exhaust system featuring stainless steel head pipes and a
lightweight, all-titanium muffler.
A
Ram Air duct not only improves the bike’s overall aerodynamics,
it also flaunts a distinct-looking, streamlined nosepiece
that allows plenty of intake area. Ribbing within the ducts
improves the ram-air effect at the sides, and offsets wind
shear from cross breezes. Meanwhile, quiet dual-radiator fans
keep the ZX-12R cool at low speeds.
For
smooth and more precise shifting, the ZX-12R’s six-speed
transmission incorporates tight clearances between the gear
dogs, while a clutch damper helps reduce driveline lash. Clutch
durability is aided by holes in the clutch pull rod and within
the clutch hub itself. The holes help increase oil flow and
contribute to an easy clutch pull.
The
ZX-12R is supported by an aluminum monocoque
frame with a cast steering head welded to pressed plates,
then welded to a cast midsection that incorporates the battery
case as a stressed member. The ZX-12R’s light steering
and planted feel is due to a steep steering-head angle.
A
43mm inverted cartridge fork with adjustable preload, compression
and rebound damping also contribute to the ZX-12R’s superb
turning characteristics. Adjustability of the fork comes from
a stepless damping adjuster, which incorporates a check valve
for improved damping performance.
Kawasaki’s
patented UNI-TRAK? rear suspension uses a linkage system to
progressively increase the damping and spring rate as the
suspension is compressed. Like the fork, the shock uses a
stepless compression and rebound damping adjuster.
Both
ends of the ZX-12R wear 17-inch wheels with hexagonal tri-spokes.
The six inch-wide rear rim is fitted with an ultra-wide 200/50
tire for excellent traction – a must for a bike as powerful
as the ZX-12R.
Braking
is accomplished with radial-mounted, opposed four-piston calipers
gripping large 320mm diameter dual front disc brakes and a
single 230mm rear disc brake. The radial front brake design
utilizes mounting points at both the top and bottom of the
caliper, with the mounting bolts inserted through the rear
of the caliper instead of the side or front as on conventional
designs. This racing-inspired setup makes the caliper more
rigid to improve brake feel over a wider range of operation.
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