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Kawasaki made some significant bo~;t;h~th:e~KX2::5:0:'S~ _IJtt',,"III""''''';~ij?~'''''1~ _ engine and Chas~s. refinements to Engine updates abound within the KX125's engine. cant. When it comes to the 250's air mixture through the transfer ports. exhaust pipe, intake system, and just pressed, resulting in smoother sus- engine, Kawasaki went hunting for Plus, a one-piece aluminum KIPS valve about everything engine related. pension action and significantly more power on top without sacrificing replacing the earlier two-piece steel All of the KX bikes received pretty its already powerful bottom-end and valve, the reshaped KIPS governor ball much the same chassis updates, the midrange. As a result, the combustion guide, and a new exhaust pipe all con- most significant change, anchoring As for the small-bore KXs, such as chamber has been reshaped for higher tribute to improve power delivery, the Uni-Trak link to the swingarm the KX65, KX85 and KX100, they're compression, the intake ports have Kawasaki claims. improved traction, especially under acceleration. rather than to the frame. Kawasaki pretty much unchanged for 2004. As been reshaped, and the new crankcase The KX 125 needed more power claims that this drastically reduces for the big-bore KX, the venerable casting eliminates the boost port at the overall, so the cylinder got reworked, front-to-back movement of the Kaya- KX500 will hang around for at least rear of the cylinder to speed the fuel- as did the power-valve system, ba shock as the suspension is com- another year. r!J7DD(fJ7] !Z(fJf21(fJ~(fJ tID ~(fJW~o 0 0 r!J7DD(fJ7] W(fJ~ @@[jfJ@ (fJ[jfJ@ WDDW eN 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. Optional 20-inch front wheel. KX250F KX125 Reshaped combustion chamber. Higher compression ratio. Piston ring locating pin moved to rear of piston to evenly distribute ring pressure at front of piston. Improved KIPS design provides better seal to piston. Reshaped expansion cham.ber provides more power and is recessed from rider's leg. Two-stage reed valve increases low-end flexibility, prevents overflexing at high rpm. New carburetor settings. Straightened air duct and carburetor holder. Revised ignition. Increased clearance between connection rod big-end and nylon crankcase "stuffer," increasing lubrication. New connecting rod made of stronger steel. Left crankcase casting is more rigid; clutch cable-to-case now sealed with an o-ring. Stronger radiator side brackets help prevent deformation. Engine bolts made of stronger steel. Stronger exhaust silencer mounting brackets and stronger igniter bracket. Chassis and suspension changes same as KX250. KX250 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 oB-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. New Uni-Trak rear suspension link is anchored on the swingarm, drastically reducing frontto-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 2mmlonger swingarm. Upper cross tubes and engine mounts are modified to idealize stiffness balance for enhanced cornering perforrnance and irnproved durability. New semisealed 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 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 Bmm. Liquid-cooled, four-stroke single cylinder engine was designed using the latest technology, resulting in a lightweight, compact and powerful engine that produces usable torque throughout the entire rpm range. Automatic centrifugal decompression system to ease starting. 37mm Keihin FCR flat-slide carburetor equipped with TPS, and the accelerator pump contributes to quick throttle response. Over-square bore and stroke of 77.0 x 53.6mm helps ensure high reliability at high rpm. Thin-wall cylinder head contributes to lightweight, compact design. Chrome composite-plated aluminum cylinder is extremely short to prevent overcooling of crankcase and subsequent power loss. Forged, two-ring piston is tin-plated to reduce wear, and the piston skirts have fine grooves to help ensure oil retention and low friction. Billet cam profiles are designed for wide powerband and high peak power. Two-stage ignition system provides low idle speed when transmission is in neutral; when in gear, it increases idle rpm for reduced engine braking. Semi-dry sump design keeps oil away from the crankshaft to reduce pumping loss and contributes to a lower center of gravity. Reed valve located between the crankcase and transmission case reduces pumping loss and prevents oil from re-entering the crank chamber. Oil feed to top-end is internal, via bolt passageways, eliminating the weight and complexity of external oil lines and increasing reliability. One-piece water pump/oil filter cover saves weight and adds to compactness. Lightweight 3-way (V-shaped) molded cooling hose eliminates need for junction and clamps. Titanium valves and headpipes, magnesium generator, outer clutch and cylinder head covers reduce overall weight. Five-speed transmission uses ratchet system for light shifting action. Clutch utilizes the same dependable components as found on the KX 125. Kawasaki perimeter frame borrows proven technology from the KX125 and KX250. New D-section upper tubing allows bodywork to "hug" the frame more tightly - the slimmer profile improves rider position for enhanced cornering. Adjustable rubber handlebar mounts help reduce vibration. Steep rake angle enhances cornering performance. Footpegs are located higher and more closely together, allowing more bank angle when turning. New Kayaba semisealed, 48mm inverted cartridge fork features check valves to control internal pressure, resulting in precise damping and better fork action throughout the stroke. New Uni-TraJ< rear suspension link is anchored on the swingarm. Rear shock features a bleeder bolt to facilitate oil changes. Front spokes are stepped both at the nipple and at the hub for lighter weight. Dual-piston front disc brake system uses Kevlar hose routed directly to the front caliper, producing strong brake performance. Lightweight rear brake system uses a lighter, compact caliper to ensure adequate clearance for the muffler when the suspension is fully compressed. Right side cover has heat shielding to deal with higher temperatures from the larger silencer. Fuel capacity is 2.0 gallons. Optional 20-inch front wheel. Optional right handlebar-mounted lever allows manual operation of engine decompression, making it easier to clear a flooded engine. eye' lIlIl n lIlIl _ os • JUNE 18. 2003 59