CK THIS OUT !
Engine Liquid-cooled, four-stroke single with DOHC and four valves
Displacement 449cc
Bore x stroke 96.0 x 62.1mm
Compression ratio 12.5:1
Fuel Injection 43mm Keihin Throttle body
Ignition Digital DC-CDI
Transmission Five-speed
Rake / trail 26.7 degrees / 4.6 in. Front suspension / wheel travel 48mm inverted, Kayaba AOS with DLC coated sliders, 22-position compression and 20-position rebound dampening adjustment / 12.4 in.
Rear suspension / wheel travel UNI-TRAK® linkage system and Kayaba shock with 50mm piston, 22-position low-speed and stepless high-speed compression dampening, 22-position rebound dampening and fully adjustable spring preload / 12.4 in.
Front tire 90/100-21
Rear tire 120/80-19
Front brake Single semi-floating 250mm petal disc with dual piston caliper
Rear brake Single 240mm petal disc with single-piston caliper
Overall length 86.0 in.
Overall width 32.3 in.
Overall height 50.4 in.
Wheelbase 58.3 in.
Ground clearance 13.4 in
Seat height 38.0 in.
Curb weight 250.4 lbs.
Fuel capacity 1.9 gal.
Color Lime Green
2010 Kawasaki KX™450F
Q & A with Product Manager Karl Edmondson
Q: I hear the stock ECU is adjustable like an aftermarket unit, but I thought fuel
injection didn’t need to be adjusted?
A: It is true that the KX450F’s fuel injection
automatically adjusts to match atmospheric
conditions. But there are other factors that a
rider may wish to tune for, like engine
modifications, throttle response, ignition timing,
etc. When we designed the current KX450F
generation, we wanted to ensure racers could
easily tune for maximum performance, so we
included a re-programmable ECU from the very
beginning. An optional ECU Setting Tool allows
racers to
select from
different data maps for SX, MX, Sand, Mud, or
fine-tune a custom map that alters fuel injection
and ignition timing to suit different tracks and
conditions. The tool can also be used as a data
logger, recording up to six hours of data,
including engine rpm, degree of throttle
opening, engine boost, coolant and air temp,
ignition timing, fuel adjustments, gear position
and system voltage.
Q: How does a “boxed-bottom” piston differ from a “normal” piston, and why
does it matter?
A: The boxed-bottom design is a more
expensive part to produce, so it‘s a rare find in a
production machine. However, when engines
are tuned for high-rpm power, stresses around
the piston pin escalate to the point that
additional reinforcement becomes necessary.
The easy way to cope with the added stress is to
produce a thicker/heavier piston. However, the
KX450F’s “boxed” piston design ties the sides of
the piston together with a rib on each side of the
piston pin. This results in a much more rigid
structure. Because the new piston is stiffer, the
length of the piston skirt can be reduced. This results in a net reduction in total
piston weight, even though two strengthening ribs were added around the pin area.
Q: What was done to boost clutch durability on the 2010 KX?
A: We designed a new pressure plate (top, right) that’s
lighter and improves oil drainage. We also changed to
new friction plates (bottom, right) with 75% more friction
material than last year’s unit. The entire assembly is
designed to provide improved clutch feel and enhanced
durability.
Q: What’s different about the 2010 swingarm?
We revised the swingarm’s center section with
narrower ribs and thinner walls, to alter its flex
characteristics. In addition to a weight reduction,
the KX450F’s new swingarm provides better turnin
and allows tighter cornering.
Q: The current 450F is doing quite well in several different racing series, so why
did Kawasaki change the suspension settings?
A: The old system already worked quite well,
but we’re always trying to improve our
products, so the 2010 rear shock received a
revised spring rate, damping settings and a
modified linkage to help increase stability and
improve impact performance when landing
from jumps. We also updated the front end
with a new steering stem, revised fork valving
and spring rates to give it a more comfortable
ride, lighter handling and less stiction during
the initial part of its stroke.
Q: The radiators are both thicker and wider; doesn’t this weight?
A: You’d think it would. However, the increased
strength of the new radiators allowed us to delete the
reinforcing brackets and the end result is about the
same overall weight as last year’s smaller/thinner units.
Also, the new radiator’s increased fin and tube pitch
give it additional strength and better resistance to mud
build-up. The KX450F’s one-piece, dual injected, twotone
green and black plastic shrouds accommodate the
new larger radiators while still providing a slim,
comfortable rider interface.
Q: Why was the header pipe material changed to stainless steel?
A: We found the stainless steel unit to be
stronger, more durable and easier to form into
complex shapes. As a result, we were able to
tuck the new one-piece stainless steel header
closer to the machine, allowing it to be 40mm
shorter for improved mid-high rpm
performance. The cleaner routing also
contributes to improved ergonomics.
