Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128158
~~WBikes 2003 Kawasaki KXs By CHRIS JONNUM 1 f one were to comb through the various motorcycle publications' motocross shootouts over the past four years, one of the words to pop up most often in regards to the Kawasaki models would probably be "old." The bikes have received minimal updates since Jesus was a lad (the plastic has been around since the '99 model year, and the bodywork that plastic replaced was remarkably similar). While the competition has undergone top-to-bottom renovations every couple of years, Kawasaki has opted to stand pat, instead offering only minor refinements that left the Kwackers feeling like something out of the vintage class. The result? KXs slipped down the charts in those aforementioned shootouts (the 125 and 250 finished fifth and fourth, respectively, in Cycle News' '02 comparisons), and Ricky Carmichael abandoned the green team for Honda (the champ sited Honda's "always hav[ing] the latest and greatest technology" as one of the reasons for his switch). No longer. For 2003, Kawasaki has given both of its two main fullsize motocrossers complete makeovers, both visually and mechanically. (The KX500 is still being offered, James Stewart Jr. has shown that he can win on the old KX 125, so just imagine what he'll do when he gets his hands on this baby, which Kawasaki wanted to be lighter and smaller, while still offering more power spread over a wider curve. To that end, the engine is all new, with a new 30mm Mikuni TMX arched-slide carburetor, a new expansion chamber, and a shorter, lighter silencer. The cylinder gets a new coating that enables a straighter exhaust-port edge for improved scavenging, and it's 6.2mm taller, with a pair of O-rings replacing the head gasket. The coolant passageways are larger in both the cylinder and the crankcases, and the radiators are larger as weU. The shifting mechanism has been re-worked to ease changing gears, and the KIPS exhaust valve is revised and coated with Alurnite. There are new reeds, and piston construction is revised, with a small window on the intake side. The crank is physically lighter, though inertia moment is up (the weight was moved to the outside). and it has plastic web covers. The crankcases are more compact, and there's a steeper cylindermounting angle. There's also a different ignition black box, which is now mounted up on the head pipe of the frame. Airbox volume is up, and the filter is moved to the left. The clutch is lighter and has a new radial thrust bearing. The transmission still has six speeds, though final-drive gearing has been altered to adapt to the different power. As for the chassis, the new frame has larger tubes, which are no longer painted green. Rake is one-degree steeper, the head pipe is 6mm longer, and there's more fork offset. The handlebar has more pullback, and even the grips are new, with a smaller diameter and a different compound. Seat foam is thicker, the chassis is narrower (at the cost of a bit less fuel volume), and the plastic is now completely different (thank goodness!). The swingarrn is hydroforrned (a process in which water is used to reshape metal) into a taper, and the rear-caliper mount is lower. Moving on to the wheels, the rear hub no longer has ridges, and there are now only four rotor mounts instead of six. The rear rotor is also larger, but thinner, and there's a one-piece rear master cylinder. Axle diameter has been increased from 20 to 25m'O, but thinner walls allow it to still drop a little weight. The brake pads us.e a new material, and the 125 gets a new rear-brake-pedal shape (it also utilizes a conventional rear rim, with no "oval" cutaway shape, and Dunlop tires). The front-disc guard is now an after-purchase option. Suspensionwise, the fork uses a non-bladder system, and it gets a rubber bumper and a lighter fork cap. The rear suspension has a new pull-rod shape, and play has been reduced on the shock. The spring rate is lighter, and there's just one compression adjuster (Kawasaki swears this makes for better bottoming-resistance than having separate high- and low-speed dials). Damping settings have of course been revised as well. According to Kawasaki, weight on the new 125 is six pounds less than that of its predecessor. though without any meaningful changes; and although Kawasaki personnel wouldn't yet comment on their four minis - some of which you'll find in yellow plastic elsewhere in this issue - they did confirm that seven KX models will be sold in '03). For now, though, we're chomping at the bit to throw a leg over the 125 and 250 you see on this page - bikes that support Product Management VP Bob Moffitt's c1anim that "Kawasaki is getting back to the bl1siness of building kick-ass, high-performance motorcycles." Finally. Now, if they would just get Kawasaki to offer a serious fourstroke. (Possible good news: Senior Media Relations Coordinator Mel Moore says "We're firmly committed to two-strokes, but we're building four-strokes as we speak. ") As we went to press, Kawasaki had still not released pricing on the KX125 or 250. eN 34 JUNE 12, 2002' cue I • Kawasaki wanted to increase the quarter-Uter KX's low-rpm response and to give it a wider torque curve, and they took several measures toward achieving that goal (though not to the same "all-new" extent of its smaller sibling). The 250 gets the same T treatment to its cylinder (and therefore the new port shape as weU), lower compression and a new rear mount. There are more teeth on the KIPS valve's gear, and said valve opens sooner as well. The inertia weight of the crankshaft has been decreased, and the main bearing is altered. Tolerances have been reduced in the transmission, there's more space between second and third gears, and there's a different shift mechanism as well. The reed valve gets a vertical "crosshair" air guide, and the clutch bushing is improved. Like the 125, the 250 gets a lighter, shorter silencer and larger radiators. All of the chassis-, wheel-, and suspension-changes that were made to the 125 were also performed on the 250, with the exception of the following: The 250 has oval cutaway rims (as opposed to standard) and Bridgestone tires (as opposed to Dunlops), and it has no new rear-brake-pedal shape. (Of course, the engine cradles are different on the two bikes, and the suspension-valving and spring-rates are appropriate for each bike.) Kawasaki claims that weight has been dropped by four pounds. n • _ s