The KX450F is officially Kawasaki’s only entry into the American Motocross and Supercross divisions. The KX250 won’t reach the U.S. shores.
Kawasaki’s flagship motocross bike, the KX450F, has a few updates for the new model year which are aimed at reducing rider fatigue and better handling. Explosive torque down low characterized the 2007 model, so the new machine gets wedge-shaped crank webs and a heavier flywheel. The Kwakker gets new ignition mapping and a redesigned piston-cooling oil jet to keep oil from getting trapped under the piston. Reshaping the shift cam and making the track wider on the shift drum allow a rider to find the proper cog with consistent, smooth shifts.
Engine mounts have been spaced 10mm farther away from the motor to decrease the torsional rigidity of the frame. This is said to aid in quicker turning and better rear-wheel traction – of which the old model had plenty.
Internal settings on the AOS Kayaba fork are stiffer to avoid bottoming and help the front end through turns. Kashima Coat treatment has been applied on the inner surface of the outer fork tubes as well as the shock reservoir.
KX250 – KX250F
As far as 250cc machinery goes, there’s only one Green quarter-liter coming to America for ’08. The KX250 has been dropped from the stateside lineup in similar fashion to the disappearance of the 2006 KX125 (which is still offered on other markets). According to Kawasaki:
This is the best looking KX250F to date in our opinion, but will the minor mechanical changes be enough to keep it in the winner’s circle?
“In order to concentrate on producing and marketing the best full size four-stroke motocross bikes in the market, Kawasaki has discontinued the distribution of the KX250 in North America. A 2008 model will be available in Europe, Japan, and Australia with the same technical specifications as the 2007 KX250.”
That leaves the KX250F, arguably the most potent Lites class machine available in 2007. With Supercross and Motocross Lites titles streaming in, the KX250F get’s a little TLC this year in order to stay on top of the game. In the motor department, new crankcases are more rigid while a new shift lever is installed for more accurate adjustment and dexterous shifting. The mounting brackets get the same 10mm treatment as the big-bore.
What in Sam Hell?!? No DLC on the 250F fork? I’d rather see that upgrade than a pair of painted rims (which are actually alumite-coated)! With the popularity of the Diamond Like Coating on last year’s 450F, it’s disappointing to see the 250 left out for another year. All anti-stiction benefits aside, if nothing else the extra black would have perfectly complemented the new rims, graphics and black numberplate backgrounds which give the little KX-F a green/black combination more wicked than ever. It’s about time an OEM started offering black backgrounds for these bikes. AMA sanctioned or not, many, if not most, local race series use the white-on-black scheme for the Lites class.
This 10mm extension on the motor mounts are shared upgrades for both KX-F models. The purpose is to reduce torsional rigidity.
The twin-chamber Showa fork has updated valving and a smaller air passage at the top of the cartridge. The piston rod is 0.5mm thicker. Changes out back are intended to support and balance the overall package.
Of course, we’ve already seen the 2008 off-road machine in the form of the smash-hit KLX450R. With Kawi using its enduro to get the early jump on the ’08 model year, will we see a 2009 KLX250R appear in the spring? Even though we hate having the release dates screwed up (reminds us too much of print magazines) we’re so anxious for that bike to appear that we’d let it slide for another season.
Let us know what you think about the 2008 Kawasakis in the MotoUSA Forum.