Killer Kx
KILLER KX
CW PROJECT
HOME-BUILT WORKS WEAPON
JIMMY LEWIS
ONE PROBLEM WITH TESTING EXOTIC, ONE-OFF WORKS bikes is that you can’t take them home. Moreover, seat time is usually limited, and despite an expensive collection of parts, the bike probably wasn’t designed for you—or your riding style.
Fortunately, we’ve discovered a solution: Build your own works bike. Sound impossible? It isn’t. Admittedly, there are plenty of parts on a factory KawasakiKX250, for example, that you can’t buy, but as we discovered, the aftermarket is overflowing with alternatives.
As a project bike, the KX250 was an easy choice. After all, it won our 250 motocross comparison, and the stylish works machines of AMA front runners Jeff Emig and Ryan Hughes had us drooling.
Prior to its conversion to works replica, our ’96 KX250 was subjected to six months of local racing. And despite a regular diet of berm busting and double jumps, only the piston and rings, the rear rim and a couple of hose clamps needed replacing.
Strong performances from Kawasaki privateers such as “Factory Phil” Lawrence led us to Anaheim, California-based Pro Circuit for guidance. Owner Mitch Payton suggested that we first sandblast the frame bare to check for stress cracks. Next, we had a local welder/fabricator beefup some of the smaller tabs, create mounting points for a skid plate and reinforce the footpeg mounts. Finally, we powder coated the frame to match the flashy fluorescent green plastic used on the factory machines.
Pro Circuit also handled the suspension. The KYB fork received the company’s Works Kit, which modifies the cartridges for a plusher and more precise feel. Included in the kit are 25mm longer, tapered chambers that are designed to eliminate bottoming. Also, compression valving was drastically altered to keep the front end from riding too far down in its stroke. As for the reservoir-equipped rear shock, the stock piston is too restrictive. It was replaced with one that has a different port design. The revised valving reflects rider weight and riding style. A heavier bumper and a works bladder cap were fitted, as were billet-aluminum linkage rods from Berg Racing. Springs both front and rear remained standard.
While the engine was out of the frame, we removed the top end. Reassembly included a Wiseco Pro-Lite piston, which is 17 grams lighter than stock. Tough, good-looking Berg Racing carbon-fiber ignition and clutch covers are held in place with a titanium bolt kit from Atomic 22. While off the bike, the radiators were stripped and re-painted natural aluminum. The finishing touch was a Pro Circuit platinum pipe and a Factory Sound silencer. Otherwise, the engine was left stock. That’s right, stock.
Chassis assembly included a set of Applied billet-aluminum triple-clamps. Lighter and more rigid than stock, the headset positions the handlebar-in this case, a Renthal Ryan Hughes bend-farther forward for a roomier rider compartment. Pro Circuit’s wider works-style footpegs were added, as were
Berg Racing’s snazzy-looking carbonfiber frame guards. The latter smooths the frame/sub-frame transition and protects the rear brake master cylinder.
The wheels remain stock, but we added oversize Braking disks front and rear. A bolt-on operation, the 10mmlarger-than-stock rotors come with billetaluminum disc carriers and replacement pads. Sunstar supplied a 51-tooth rear sprocket, which we mated with the stock countershaft sprocket and DID’s new #520 MX chain. Dunlop’s K490 front and D737 rear knobbies were used in hardpack conditions while softer stuff called for a D755 front and a D757 rear.
Acerbis fluorescent-green factory replica plastic was the final touch, held in place with additional Atomic 22 titanium-and-aluminum fasteners. The fenders, sidepanels and radiator shrouds received Factory Effex Team Kawasaki graphics, just like the works bikes. Factory Effex also supplied the numbers and background plates. Wide Open Racing’s Team Kawasaki Lo-Grip seat cover replaced the stock vinyl. The carbon-fiber/kevlar fork guards and carbon-fiber sliders are from Berg Racing. Even the master cylinder gets in on the action with its own lightweight carbon-fiber rock guard.
Despite our KX’s showbike appearance, we couldn’t wait to get it muddy, so we headed north for the 29th Annual Mammoth Mountain Motocross, the perfect outdoor venue for serious roosting.
The CW KX250 has a distinctive bark. Even at 8000 feet above sea level, the engine feels significantly more responsive than stock-the lighter piston plus the pipe and muffler make a difference. There’s more power everywhere and a Flonda CR250-like crispness. The only jetting change was a switch to a leaner, #8 slide and a one-size-smaller, #158 main jet. Just to be on the safe side, we mixed 92octane pump gas 50/50 with F&L race fuel.
From the first lap, the bike felt solid. The new triple-clamp and handlebar made for a roomier cockpit, the wider footpegs offered extra grip, and the Lo-Grip seat cover gave the bike a betterthan-new feel. In short, all the KX’s strong points were emphasized. Take the brakes, for example: The oversized rotors give new meaning to the phrase, “powerful binders.” They’re better than Honda’s class-yardstick brakes with even greater control. Also, the harshness exhibited by the stock shock is gone. The fork no longer bottoms, yet the stock unit’s plush feel was retained. Handling, as well, is as solid and stable as ever.
There’s not much to say about the exotic carbon-fiber parts-everything held up well. Did the big-buck pieces affect the bike’s weight? Most likely, but the overall weight of the bike jumped one pound to 227 pounds, without gas-blame the powder-coated frame, added mounts and skidplate. Riding the bike, I didn’t notice a weight difference. Mostly, the carbon-fiber, the flashy plastic and the stickers just attracted a lot of attention.
In our 250 motocross shootout, we proclaimed the KX250 the hands-down winner because it “would take the least amount of work, tuning, time or dollars to get it set-up for competition.” Okay, so we ignored reason and fell prey to a healthy aftermarket. So what? In return, we got the best bike available short of one pulled from the Kawasaki race-team transporter. While everyone else is gearing up for Honda’s aluminum-framed ’97 CR250R, we’re already roosting. □
SUPPLIERS
ACERBIS PLASTIC 9204 Wheatlands Court, Suite A Santee, CA 92071 619/562-1440 Front fender: $17 Rear fender: $20 Radiator shrouds: $38 Side panels: $41
ATOMIC 22 6821 Fleur Drive Des Moines, IA 50321 800/964-4332 Front end fastener kit: $120 Engine cover kit: $130 Plastic fastener kit: $95
APPLIED MANUFACTURING, INC. 1115 Industrial Avenue Escondido, CA 92029 619/743-8190 Top triple-clamp kit: $135 Bottom triple-clamp: $113
BERG RACING 2291 1/2 South Grand Ave. Santa Ana, CA 92705 714/754-1918 Ignition cover: $140 Clutch cover: $160 Frame guards: $90 Front brake reservoir guard: $35 U.S. Carbon/kevlar fork guard: $52 U.S. Lower fork shield: $90
Chain guide plate: $40 Linkage pull rods: $85
BRAKING 820 Manhattan Ave., Suite 101 Manhattan Beach, CA 90266 310/798-4830 Front oversize rotor kit: $200 Rear oversize rotor kit: $250
FACTORY EFFEX 28209 Ave. Stanford Valencia, CA 91355 800/840-3040 Team Kawasaki graphic kit: $60 Team Kawasaki trim kit: $60 Numberplate background set: $15 Numbers: $6 per set
MOTO MAN DISTRIBUTING P.0. Box 1037 Chino, CA 91708 909/391-3278 D.I.D #520 MX chain: $103
PRO CIRCUIT 4214 East La Palma Anaheim, CA 92807 714/993-5400 Shock revalve and setup: $135 (plus parts and oil) Works KYB bladder cap: $35 KYB heavy bumper: $15
Fork revalve and setup: $135 (plus parts and oil) Works KYB fork kit: $178 Platinum pipe: $180 Factory Sound silencer: $73 Handlebar clamp: $60 Works footpegs: $100 Skidplate: $62
RENTHAL 24950 Anza Drive Valencia, CA 91355 800/222-4296 Ryan Hughes-bend handlebar: $90 Medium-compound grips: $11
SUNSTAR ENGINEERING 307 Paso Tesoro Walnut, CA 91789 909/598-9666 Works Triplestar rear sprocket: $64
WIDE OPEN RACING 12754 Ventura Blvd., Suite B Studio City, CA 91604 818/760-0220 MXA Lo-grip seat cover: $78
WISECO 7201 Industrial Park Blvd. Mentor, OH 44060 800/321-1364 Pro-Lite piston: $95 Gasket kit: $35
