Cycle News - Archive Issues - 1990's

.RIDING IMPRESSION By Cameron Coatney Photos By Kit Palmer and Coatney W \0 0\ 0\ '""" 00 '"OJ "" I-< "S ~ £" 2 e had a love/hate relationship with the 1996 Kawasaki KX250 - we loved the power it produced and the way it handled but we hated the purple color scheme. Purple was the hip color for bikes to be splashed with in the early '90s, but Kawasaki got into ita little late and purple just didn't jive with the green anyway. We knew we weren't the only ones who disliked the purple when Team Kawasaki showed up at the Orlando Supercross sporting greener than green race bikes - the frames were painted fluorescent green and Acerbis whipped up some fluorescent green plastic to match. Now that's a Kawasaki. We knew the bike performed well, though, and it was one of the favorite bikes in our '96 test fleet. And we all know just how potent the bike was in the right hands - just look at Team Kawasaki factory rider Jeff Emig's 1996 results. He was the only rider able to 1997 Kawasaki. KX250 stop Jeremy McGrath's Supercross win streak_when he beat McGrath at the St. Louis SX and finished second in the series, and he won a head-to-head battle with McGrath to take the 1996 AMA National Motocross Championship last week in Steel City, Pennsylvania. The bike was good - and it got even better for 1997. Read on. Kawasaki performed some minor changes on the 1996 KX250 that worked well, bu t this year they decided to up the ante a little bIt by diving into the 1997 KX250'and making many, mosdy internal, changes. ~osmetically, the first thing you'll notice is the return to the green radiator shrouds and white fork and radiator guards, Sources say that these units share the same part numbers with the 1995 KX250. Whatever the case may be, we like this look a lot better - it's not so in your face. Kawasaki made changes to the motor that emphasized a gain in top-end power, without losing any of the bike's good low and mid-range power characteristics. A new main valve shape for the three-way I<;awasaki Integrated Power Valve System (KIPS) produces a £lush fit with the main exhaust port. The result is superior sealing and reduced exhaust gas pressure for better mid-range and top-end powe:t;. The piston utilizes .2rnm thinner piston rings to cut friction and further increase the power at high rpm. A new expansion chamber is 40mm shorter in an effort to produce more topend power, especially in the over-rev department. The redesigned exh,aust system is now finished in a dark metallic gray instead of black, and is tucked up further and to the left for greater ground clearance and crash protection. The silencer now gets a tail cover like the factory bikes to prevent mud from clogging 'the outlet and a costly ONF. Low to mid-range pow!'!I was said to increase by revising the intake tract. A new four-petal reed valve unit replaces the eight~petal unit and responds better at low engine speeds for more torque. Epoxy resin reed valves are fitted in place of the carbon fiber reeds from '96 for increased durability. The new intake boot and r.eed valve air guide increase intake velocity for better fuel atomization to further improve low-speed and mid-range throttle response. An all-new timing map in the COl unit matches all of the engine changes and compensates for the top-end tuning bias. The KX250 sti11 is fed its fuel through a Keihin PWK38 carburetor. If you don't remember, Kawasaki introduced this breakthrough carburetor on its MX line last year. It features what Kawasaki calls "bat wings" attached to the air funnel to increase intake air velocity for better fuel atomization and improved low and mid-range throttle response. A heavier crankshaft was used to smooth out the power delivery and enhance traction. Higher gear ratios in seCORd, third and fourth gears, plus a higher final drive ratio, match the engine's new power curve. The shift mechanism was borrowed from the 1997 KX125 to improve shifting, while clutch feel was improved with a new release cam, push-rod and cable. Larger box section beams in the hightensile steel perimeter frame increase rigiclity and larger footpeg brackets are stronger for greater durability. The footpegs now are cast steel and are much larger, and should pe able to keep the largest of feet planted. The bike received the huge swingarm that the factory started using in mid-season (when Emig started holeshotling SX races) that is 18mm longer and has a larger hollow-cast aluminum cross sectio ll in the pivot area for increased rigidity. The swingarm connects to the shock on the redesigned Uni-Trak rocker arm that provides a more progressive suspension action. The 46mm Kayaba forks have gone to a non-circulating bleed system that is said to be plusher than past models. The fork cylinders were increased by 4rnm in size to displace more oil for more accurate damping control. A new trench-type piston for the compression and rebound damping valves further improves suspension feel, and the bottoming cone has a 5mm larger taper to soiten harsh landings. . The front brake master cylinder is now smaller in diameter to reduce the pressure needed at the lever, and a new brake caliper now bas smaller pistons that are made out of steel instead of plastic. The front brake line had to be rerouted and takes an even shorter and more direct route than last year, which makes service easier. . In the rear, the brake caliper holder was revised to fit the new swingarm • and the brake pedal was redesigned for better feel and controL The rear hub picked up an extra bearing on the drive side, and the hub oil seals have been improved for increased durability. The chain guide sideplates were thickened and a more durable urethane chain block resides within. The KX250 now comes stock with Bridgestone tires instead of Ounlops. The front tire is a Bridgestone M77 and the rear tire is a M78 - both solid intermediate condition performers. The rear tire comes in a dual tread compound that is harder in the middle and soiter on the sides for increased traction when leaned over and increased wear in straight-line conditions. The rear tire is exclusive to the KXs for now. The changes were plentiful this year and you're probably wondering if Kawasaki messed up a good thing. It clidn't. The bike is solid at every l!!vel of performance - still. The KX250 has great motor that is hard to find faul t with. The bike has the kind of tractable power that makes a bike easy to go fast on. The power

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