A host of new refinements increase performance and handling
Kawasaki Motors Corp., U.S.A., diligently refines its KX racing motorcycles to a very fine pitch. Starting with simple but powerful designs, Kawasaki studies the lessons learned from the previous year of competition to make the next model faster, better handling, and easier to ride.
The KX250 for 2004 has received a host of refinements resulting in increased engine performance, improved handling and greater rider comfort.
To give the 249cc two-stroke engine excellent top-end without sacrificing hard-hitting low- to midrange power, the combustion chamber has been reshaped for higher compression, the intake ports have been reshaped, and the new crankcase casting eliminates the boost port at the rear of the cylinder to speed the fuelair mixture through the transfer ports. Plus, a one-piece aluminum KIPS® valve replaces the earlier twopiece steel valve, the KIPS governor ball guide has been reshaped, and new expansion chamber dimensions all contribute to improved power delivery.
Other improvements include new carburetor settings that provide crisper response at partial throttle, reshaped air duct and intake manifold for straighter airflow. New ignition timing and ignition rotor also contribute to improved power across the entire rpm range.
To further enhance throttle response, the crankcase “stuffers” mounted to the crank webs have been changed from aluminum to nylon and lead inertia weights have been eliminated.
Piston durability has been improved by “streaking” the skirt with fine oil-retaining grooves and by tin-plating the piston.
The most significant change to the KX250 chassis is the new-link UNI-TRAK® rear suspension system. Unlike previous KX models in which the UNI-TRAK link was anchored to the frame, the link on the new system is anchored on the swingarm. This drastically reduces front-to-back movement of the Kayaba shock as the suspension is compressed, resulting in smoother suspension action and significantly improved traction, especially while accelerating. The revamped UNI-TRAK rear suspension provides 12.2 inches of travel enhanced by 16-way compression and rebound settings.
Also, the thickness and shapes of the upper cross tubes and engine mounts have been modified to idealize the stiffness balance for enhanced cornering performance and improved durability.
A new Kayaba 48mm, works-type semi-sealed cartridge inverted fork with 11.8 inches of travel handles front suspension duties for the KX250 and features 16-way compression and rebound settings. Other modifications include more compact axle brackets with a new clamping method.
The front brake line is now routed directly to the single-disc brake caliper rather than under the bottom of the fork leg as on the previous model, resulting in a slightly lighter brake hose, producing improved brake feel and simplifying maintenance.
Other changes include restyled fork guards and a stronger chain guard of more durable material. Seat height has been raised 8mm in the middle for a flatter profile and the seat itself features a new textured slipresistant cover. Plus, the fuel tank uses an oblong mounting hole for easier maintenance.
A host of optional parts for the 2004 KX250 are available through Kawasaki dealers, including a lower seat, 20-inch front rim, a selection of aluminum and steel front and rear sprockets, different fork and shock spring rates and solid brake discs.
All KX motorcycles come with the support of Team Green„¢, Kawasaki’s amateur support program. Team Green’s regional support vehicles and highly trained technicians provide technical information and assistance for anyone who rides or races a Kawasaki. Team Green also offers a comprehensive contingency progr for amateur and professional riders who place well at designated events.
Information about the KX250 motorcycle and Kawasaki’s complete line of family recreational products can be found on the Internet at www.kawasaki.com. Accessories for KX motocross bikes can also be purchased online at www.buykawasaki.com.
Kawasaki Motors Corp., U.S.A., (KMC) markets and sells at wholesale Kawasaki motorcycles, ATVs, JET SKI® watercraft, MULE„¢ utility vehicles, power products and small engines. Kawasaki’s tagline, Let the good times roll„¢, is recognized worldwide for the spirit of fun, adventure and high performance that characterizes the Kawasaki recreational vehicle line. Kawasaki product lines are sold through a network of more than 1,500 independent retailers. The company and its affiliates employ nearly 2,400 people in the United States, with approximately 550 of them located at the Irvine, California headquarters.
2004 KAWASAKI KX250
Features and Benefits:
Numerous refinements to the liquid-cooled, two-stroke engine result in improved power. These include:
- Reshaped combustion chamber
- Higher compression ratio
- Revised intake ports
- Revised exhaust port timing
- Straighter carburetor air ducts
- Reshaped two-piece KIPS® valve and governor ball guide, new KIPS® cover breather
- Crankcase “stuffers” mounted to crank webs are changed from aluminum to nylon
- Piston “streaking” with fine oil-retaining grooves and tin-plating enhances seizure resistance, improving durability
- New engine mounting bolts made of stronger material
- Steel pin pressed into kickstart stopper prevents stopper area from wearing and kickstart lever from angling out excessively
- Stronger radiator side brackets help prevent deformation
- Relocated expansion chamber bracket
- Stronger chain guard uses more durable material
Chassis and Suspension
- New UNI-TRAK® rear suspension link is anchored on the swingarm, drastically reducing front-to-back movement of the shock, resulting in smoother, more stable action and improving traction at the rear wheel when accelerating
- Forged, one-piece actuating rod for UNI-TRAK replaces two-piece extrusions
- Frame construction is lighter due to suspension loads being absorbed by the new 2mm longer swingarm
- Upper cross tubes and engine mounts are modified to idealize stiffness balance for enhanced cornering performance and improved durability
- New semi-sealed cartridge fork provides better damping and fork action
- Front axle is 9mm shorter and axle collar is shorter and lighter (both are common with the new KX250F)
- More compact front axle brackets feature new clamping method
- Adjustable rubber handlebar mounts help reduce vibration
- Flatter seat improves riding position and raises seat height 8mm
- Textured slip-resistant seat cover helps keep rider in place
- Footpegs raised 3mm to suit the improved riding position
- Rear brake pedal pivot is mounted 11.5mm higher for increased ground clearance
- Fuel tank uses oblong mounting hole for easier maintenance
Kawasaki Options (Available Through Kawasaki Dealers)
- Carburetor tuning parts, head gaskets of different thickness, ignition rotors with varying inertia weights, aluminum and steel rear sprockets
- Flywheel rotors allow riders to alter the amount of engine inertia to suit riding style and track conditions
- 20-inch front wheel, solid brake discs, softer and stiffer suspension springs
2004 KX250 SPECIFICATIONS*
|Engine||Two-stroke single with KIPS®|
|Bore x stroke||66.4 x 72.0mm|
|Carburetion||Keihin PWK38S with Power Jet|
|Induction||Piston reed valve|
|Compression ratio||10.1:1 (low speed), 8.9:1 (high speed)|
|Ignition||Twin Spark Digital CDI|
|Frame||Perimeter style, high-tensile steel with aluminum subframe|
|Rake/trail||27° / 3.8 in.|
|Suspension type, front||Kayaba 48mm inverted telescopic|
|Suspension adjustments, front||16-way preload and rebound damping|
|Suspension type, rear||UNI-TRAK® swingarm, single shock|
|Suspension adjustments, rear||Spring preload, 16-way compression and rebound|
|Wheel travel, front||11.8 in.|
|Wheel travel rear||
2004 KX250 SPECIFICATIONS*
*Specifications subject to change
font size=”2″ face=”Arial, Helvetica, sans-serif”>12.2 in.
|Tire, front||80/100 x 21|
|Tire, rear||110/90 x 19|
|Brakes, front / rear||Hydraulic disc|
|Overall length||85.6 in.|
|Overall width||32.5 in.|
|Overall height||47.4 in.|
|Ground clearance||14.0 in.|
|Dry weight||213.8 lbs.|
|Fuel capacity||2.2 gal.|
|Color||Kawasaki Lime Green|
*Specifications subject to change