2006 Kawasaki KX250F

2006 Kawasaki KX250F: Lean, green machine

Story by James Holter, photos by Kinney Jones

Now, this is playing dirty.

Kawasaki Motors Corp. introduced the 2006 KX250F at the immaculate and exclusive Castillo Ranch Motocross Park in central California. Handing a new bike to the press corps in the middle of moto-heaven-on-earth feels a little like bribery.

But they didn’t have to go that far—honest! The new machine is fast, feels light and the Showa suspension—a first for any KX, according to the Kawasaki technical team—works great.

The 2006 KX250F marks the model’s first departure from the Kawasaki/Suzuki partnership that gave us the KXF/RMZ250, which were identical except for colors in 2004, and colors and stock jetting specs in 2005.

Under the previous relationship, Kawasaki was responsible for the chassis, and Suzuki built the engine. For the 2006 models, Kawasaki has an exclusive aluminum frame for the KX250F. Visually, the frame matches the aluminum frame on the all-new KX450F, which will be officially rolled out later this year.

While the frame is the most obvious change, the boys in green are also boasting Kawasaki-only changes to the engine that are designed to improve the mid-range hit and over-rev. The intake and exhaust ports were revised, the cam profiles are new and head work boosts the compression to 13.5:1 from last year’s 12.6:1.

Other changes targeted reliability. The piston has a thicker crown, the valve springs are stiffer, the tranny is beefed up, oil pump flow is increased by 20 percent, and the radiators have more tightly packed cores to cool better.

All that adds up to a great performing bike.

The power doesn’t come on with a monster hit, but it’s very lively. Best of all, it pulls solidly into the upper RPMs, but still makes enough juice down low that you don’t have to bang on the clutch out of corners.

Starting the bike was a breeze. The higher compression ratio was a non-factor, thanks to the revised timing and lift of the decompression system. The KX250F kicks over as easy as a minibike and starts almost as effortlessly.

Shifting was a toe-tap affair with the five-speed tranny, and the clutch pull was smooth and light.

Kawasaki has traditionally been a purveyor of Kayaba suspension goods, and the Showas are an obvious break from that tradition. It was a move that paid off. The fork soaks up both small chop and big hits.

While the move to the new suspension might have been a big leap, the new aluminum frame has to be considered an even riskier move. The completely new design resembles Honda and Suzuki’s twin-spar approach, a set-up prone to rigidity if not done right.

Kawasaki did its homework, though. The bike handled very well. There was some slight pushing through tight loamy corners, but that may have been due to the intermediate-terrain Bridgestone that is the stock tire on the bike (and worked fine where the track was worn in).

The total package was a fun and potent weapon on the hilly and perfectly prepped Castillo Ranch track.

2006 Kawasaki KX250F
Engine	249cc four-stroke single
DOHC	four valves
Carburetion	Keihin FCR37
Rake/trail	27.7 degrees/4.7 inches
Front suspension	47mm twin-chamber forks 16-way compression and rebound damping 12.4 inches of travel.
Rear suspension	High- and low-speed compression damping 17-way rebound damping 12.2 inches of travel.
Brakes	250mm front disc , 240mm rear disc.
Wheelbase	57.8 inches
Ground clearance	14.6 inches
Seat height	37.8 inches
Fuel capacity	1.9 gallons
Dry weight (claimed)	204 lbs.
MSRP	$5,899

James Holter

KX250F 2005 kawasaki