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/126947
Ttte Kawasaki is a mellow turner but,good low-end makes it blast out of the comers quickly. The five-speed transmission has a slightly taller overall gear ratio. and the clutch has a much smoother feel compared to the 1986 KX250. Test: 1987 Kawasaki KX2S0 Mean, green and seeingred By Kit Palmer Nineteen eighty-six wasn't a bad year for Kawasaki motocrossers. In fact, it was a very good year. The 1986 KX250 was an exceptionally good piece of racing equipment, but it had ,one problem - the 1986 Honda CR250. But 1987 could be a different story. Kawa ak.i went all out this year to produce a 250cc motocrosser beller than Honda's, and the two most not· able changes to this year's KX250 is the all-new frame and longer stroke motor. Beginning with the chassis, the 250 now has tlte same type of frame de ign as la't year's good·handling KX 125. The noew frame has separate [rant and rear sections; the front is constructed of high·tensiJe steel, and the rear sub· frame section is made of lightweight box-section aluminum. Used with the updated frame design is an all-new Uni-Trak rear susPension system, which elirrtinates the use of the old strut and bell crank system. The bollom of the shock now con· nects to linkages beJow the swing· arm. There are a few good reasons for this new design. It enables the shock to be mounted farther forward and lower in the frame to help centralize and improve the bike's center ofgravity. Plus, it allows Kawasaki to use a larger aitbox for better breathing. The shock itself is all new, too. It's a Kayaha unit that now features a piggyback reservoir instead of the old, less reliable and less effective remote reservqir design. There are two l6-way compression and rebound adjustment knobs mounted above and below the shock body. The shock aJso has fully adjustable preload. Rear wheel travel has been increased from l2.5 inches to 13 inches, and seat height is now slightly taller. Up front, the KX features what Kawasaki calls a Floating TCV (Trav· el Control Valve) fork. The 43mm Kayaba fork is similar to last year's design but features new "floating" push rods that are no longer mounted rigidJy to the main spring retainer on the TCV. The company claims this new design assures plusher fork action throughout 11.8 inches of wheel travel. At the bottom of each fork leg are l6-way adjustable compression . damping screws, but gone for '87 are preload adjusters. The KX uses [ront and rear disc brakes that feature some changes. The front, single·piston caliper has a 25% larger pad and a 12% larger piston, for what Kawasaki claims is a 20% increase in stopping power. In the rear, the brake pad is made out of different material for lower friction to produce smoother operation. A steel-braided brake hose is used up front. The KX's two-stroke, water-cooled engine features a smaller 67.4mm bore and a longer 70mm stroke with 249cc displacement. The longer stroke motor is designed to give the Kawasaki more tractable low-end and mid· range; to boost rrtidrange and top end power, the Kawasaki Integrated Power-Valve System (KIPS) was mod· ified. The major KIPS components include an exhaust resonator, two auxiliary exhaust sub-ports, two valves that open and close the resona· tor and sub-ports, and a crankshaft· driven ball·ramp governor. The 1987 KIPS power valves are larger and have bigger openil)gs to increase ex-. haust flow from mid to high rpm. The width of the valve openings has gone up from 15mm to 23mm, and the diameter of the sub'ports have been increased from 18mm to 2lmm. Other changes to the KIPS include new left-side power valves that are now made out of aluminum instead of steel, and the governors gears are now' plastic - this was all done to reduce weight. The whole unit has less moving parts than before. The cylinder is made out of alumi· num but is lined through an Electro· Fusion process which forms a thin and strong lining that reduces weight, dissipates heat more efficiently and increases-the life span of thecyhnder, according to Kawasaki. Plus, the aluminum piston has a new dome top, which combined with a modified combustion chamber increases compression ratio to 10.6: I. Carburetion is handled by a 38mm, R·bouom slide Mikuni with a smaJler Kawasaki KX250 Enginetyt:ie ••••• Liquid-caaIBd. 1WO-lItrCIke. 8iRgIe Bore x sttoIce •... 67.4x70.o-n DispIK_ _lt 249cc COOnpi-*>n ratio ..•... 10.6:1 Carburetor . • • . •. 38mm Mikuni Horsepo N/A Torque N/A Staning ~ ' Prim-v kick Ignition. . . . . . . . . . . . . . . . . . COl lubrication. . . . . . . . . . .. Premix Primary drive Straigtlt-eut gHrS Final drive ,............ Gear ratios Primary 55/20; Final 47/14; 5tt1 24/24; 4tt1 ..' 25/22; 3rd 25/18; 2nd 30/17; 1st. 32/15; Chain 2.750 3.357 1.000 1.136 1:388 1.764 2.133 Frame . . . . . . . Single downtube. split double cradle RIlIre : • _• •. 2SO Trait•.•..•. , •••..... : .. 4.7 in. F__ "SIlII 1'1 , .•• Telncnpic fork Fork ~ diametel' •••... 43nml Front wheel travel •.•... 11.8 D. . . . . . . . . .sion •.....• Single.' sIlock. swingMm Reer ..... travel ..••.• 13.0 in. Front braes 8.7-in disc Reer bnIIces ~ .. . . . . . 7.s-in disc front tire •. 80/100·21 Dunlop Reer tire .. 100/100-18 Dunlop CI8itned dry _ight .. 212.7 Ibs Overalilength 86.6 in. . Overall width 32.0 in. Overall height ....•.... 48.2 in. Whee1base 59.0 in. Ground clearance .. " .. 14.8 in. Seat height 38.2 in_ Colors . . . . . . . . . . . . . . . . . Green Retail price $2899