Kawasaki KX250F User Manual

2011

Specications:

KX250YBF

Engine Type 4-Stroke, Liquid Cooled, DOHC, 4-Valve, Single, DFI

Displacement 249.0 cm³

Bore & Stroke 77.0 x 53.6 mm

Compression Ratio 13.5:1

Fuel System Keihin 43 x 1, Digital Fuel Injection

Ignition Digital DC-CDI

Transmission 5-Speed

Rake/Trail 27.4°/ 118.6 mm

Front Wheel Travel 315 mm

Rear Wheel Travel 310 mm

Front Tire Size 80/100-21

Rear Tire Size 100/90-19

Front Suspension Separate Function front Fork, 47 mm Inverted Twin-Cham-

Rear Suspension

Wheelbase 1,475 mm

Front Brake

Rear Brake

Fuel Tank Capacity 7.2 litres

ber cartridge-type fork with 22-way compression and 20­way rebound damping adjustment, 60-way spring preload.
Titanium Oxide Coating.

New UNI-TRAK with gas-charged shock absorber
which features fully adjustable spring preload, 17-way
rebound and 13-way (low-speed) and 2 or more turns of
high speed compression damping adjustment.

Semi Floating 250 mm Petal Disc & Twin Piston Calliper

240 mm Petal Disc & Single Piston Calliper

Key Features:

Digital Fuel Injected Engine

Separate Function Front Forks

Revised Aluminium Chassis with Improved

Handling

Ground Clearance 330 mm

Seat Height 945 mm

Curb Mass 105.7 kg

Colours Lime Green

(Specications subject to change without notice.)

(Includes full fuel tank and all uids at correct levels)

2011 KX250F

High-Performance, Fuel Injected, Liquid Cooled,
4-Stroke Engine in Race Winning Chassis

There are nearly 30 upgrades to the 2011 Kawasaki KX250F,
reecting the rigor of testing and development happening at
Kawasaki. Engineers started with what’s arguably the gold
standard in 250-class racing – the 2010 KX250F – winner of
the 2010 AMA East and West Supercross Lites titles.

Loads of engine modications have made the latest KX an
absolute corner-to-corner screamer. Renements to the
249cm³ single include higher compression, a modied top
on the exclusive Bridged-Box Bottom piston, higher valve lift,
longer spark plug design, and a new coil that offers a hotter
and longer-lasting spark. And, the addition of Digital Fuel
Injection (DFI) produces stunning – and more useable –
power. The system automatically adjusts to suit track and
climate conditions, even when the going gets rough.

- Exhaust revison to meet stricter noise regulations

High-speed Chassis with Factory-styled components
and tuning

- Separate Function fron
Fork (SFF) offers signicantly
reduced friction to realise
smooth fork action and rm
damping performance (rst
time used on a
mass-production
motorcrosser)

- Left fork tube: damping
assembly

An optional ECU Setting Tool allows racers to select from
several different ECU data maps or ne tune a custom map.
The tool can also record up to six hours of data, including
engine rpm, degree of throttle opening, coolant and air
temperatures, ignition timing, fuel adjustments, gear
position and system voltage.

Headlining the chassis changes on the 2011 KX250F is
Kawasaki’s new Separate Function Fork. Instead of a
conventional fork design, the SFF separates spring and
damping duties (one in each leg) for improved performance,
less friction, lower weight and easier adjustability. The right
leg has the spring, with a larger main spring/rod assembly
than traditional forks; the left leg handles damping, with
rebound and compression damping adjustable on the fork
tube.

As for ergonomics, the KX250F’s bodywork offers riders a slim
interface and a natural positioning that make going fast a sim­ple affair. The upgraded seat provides excellent seated grip
and rider mobility, and features rm urethane foam to hold
its shape longer.

MORE POWERFUL, FUEL INJECTED ENGINE

- Specs on par with our Factory
Racers

- Strong power at all engine
speeds

- Quick throttle response

- Superb over rev charactoristic

- High-performance piston
with bridged-boxed bottom
(unique Kawasaki feature
among mass-production
models) straight from our
Kawasaki Factory Racers

- Light weight battery-less
fuel injection system

- Stronger low and mid
torque allows riders to corner
a gear higher (less shifting)

-KX FI calibration Kit
(optional) indentical to our
Factory Teams

- Right fork tube: spring

Benets include:

- reduce friction (-25%) =
increased riding comfort

- space for preload adjuster
(simplies task of setting fork
preload or ride height)

- race friendly: suspension
jobs are quicker and easier

Chassis ne-tuning for revised rigidity balance results in
increased lateral chassis ex

Benets Include:

- lighter turning

- increased front wheel traction

- more planted feel from front wheel

- enhanced cornering accuracy
Control maintained during high-speed (in straights and when
cornering)

Factory Styling

- agressive graphics

- blacked out rims

- blue alumite1 nish on fork adjuster and rear
suspension upper adjuster

AT A GLANCE

Factory Inspired Tuning

Tuned for high performance, the wide
powerband extends way into the over­rev. A works-base bridged-box bottom
piston (used for the rst time on a
mass-production motocrosser on the
10MY KX250F) is
just one of the
features inspired by
our factory racers.

All-aluminium perimeter frame

Slim perimeter frame is
lightweight construction
composed of forged, extruded
and cast parts.

Reduced Noise

Changes to mufer internals
ensure that stricter noise levels
are met.

Rear Shock Absorber

Dual compression adjustabil­ity offers a wide range of tuning
options.
Kashima
Coat on
the tank
cylinder
improves
action.
Revised
damping
settings
contribute
to improved action and increased
absorption performance

Seat

Revised pattern for
the seat side offers
more grip.

Slim Rider Interface

Bodywork components
and seat design offer a
slim, natural riding
position making it easier
to for racers to go fast.

Renthal Handlebars

Factory-styled
handlbars and pad
saves weigth.

Factory-styling

Factory-style graphics, black alumite1
rims, black fork guards and blue
alumite1 nish on the fork adjusters and
rear suspension upper
adjuster give the
KX250F the looks to
match its highly tuned
performance.

Separate Function Front Forks

Used for the
rst time on a
mass-production
motocrosser,the
SFF locates its
damping assembly
in the left fork tube
and a spring in the
right. Signicantly
reduced friction
makes it possible to
realise the combi­nation of smooth
action and rm

damping perform­ance. The addition of a preload
adjuster facilitates machine setup.
Improved left/right balance con­tributes to handling. Low-friction
titanium coating (unique in this
class) smoothes fork action.

Lighter Handling Chassis

Increased chassis ex, revised
rigidity balance and reduced fork
offset result in lighter turning,
increased rear wheel traction, a
more planted feel from the front
wheel and enhanced cornering
accuracy.

Setting-adjustable motocross
ECU

Lightweight
ECU was
designed
specically
to withstand
the rigors of
motocross
racing. Settings can be repro-

grammed with an optional KX FI
Calibration Kit.

Petal Disc Brakes

Front
and rear petal
brake disc
offer efcient
braking

performance

Liquid-cooled, 4-stroke Single with Digital Fuel Injection

Now fuel-injected, the engine
offers the same high-revving
performance while ensuring stable
fuel-metering in all conditions.
A new piston crown and higher
compression ratio offer increased
high-rpm and over-rev, while a
deep-protrusion spark plug and
revised intake ducting contribute
stronger low-mid torque.

Less Missed Shifts

revisions offer more accurate
shfting

Shift mechanism

Lightweight Fuel Pump

Newly designed
fuel pump located
inside fuel tank is
a lighweight
construction

Progressive Throttle Link

Lightweight 43 mm throttle body
uses two
shafts joined
by a pro­gressive link
to give sharp
response
and excellent power feeling

New Uni-Trak Rear Suspension

Linkage mounts below the swingarm
for more precise suspension tuning.