Loud and brutally fast - that about sums up the Kawasaki KX250F over the years. Kawi’s small-bore motocrosser is continually at the front of our shootouts as one of the bikes that does everything well. It enters our 2010 competition with very few off-season changes to brag about, but that proved to have little effect on its warm reception. The Yamaha and KTM in particular seemed to have high and low opinions, but the KX-F was universally liked.

Engine:
What, no fuel injection? That was the initial reaction from most people, us included, once they heard the 2010 KX250F wasn’t getting the trickle-down technology from its big brother. The first time we clicked the quarter-liter into gear and effortlessly released its clutch, it was the last time EFI was on the discussion table. This bike flat out rips. Every rider was completely stoked with the Kawi’s snappy, full-figured powerband. “It feels like a slow 450,” says Garcia. “It’s that fast.”

A new bridged-box piston with revised crown and shorter skirt and piston pin moves inside the cylinder, cranking out alarming mounts of forward momentum with revised intake ports targeting better top-end. The titanium exhaust header tapers from 35mm to 45mm for better throttle response and it gets a new muffler can as well. Piru and Glen Helen are tracks that feature plenty of uphill sections, but more effort from the right wrist equals less work for the clutch fingers. The KX-F pulls hard everywhere. If there’s any chink in its armor (more of an insignificant scratch, really) it's in the very low rpm where the Yamaha’s grunt and Honda’s instant response put up a fight. Don’t be fooled by peak numbers, every rider felt that this was easily in the top-two in terms of speed. Fueling from the 37mm Keihin carburetor was faultless during our tests, prompting several testers to compare its efficiency with the CRF’s EFI system.

“Despite still employing a carburetor, jetting is spot-on perfect,” exclaims Waheed. “The motor accelerates flawlessly without any hesitation or hiccup, even when landing off jumps with heavy throttle load. It almost feels like the engine is burning race fuel because the motor responds so instantaneously to throttle input. If Kawasaki can keep producing bikes that run this good out of the box then I don’t see any need to add fuel-injection.”

WMX rider, Bash, has plenty of experience on Kawasakis, racing them during her amateur and professional career. She too was blown away by the competitiveness of the stock KX-F engine. “You can take it out of the crate and to the starting line and be just fine,” she says of the new model.

Suspension:
Kawasaki provides a bike with exceptional balance. Not as forgiving as the Yamaha, but more well-rounded than the KTM and Honda. The KX-F’s smooth action and progressive bottoming resistance make for a confident ride. Multiple testers note the Kawi’s even keel front-to-rear and cite it as one of the most endearing features of the Showa suspension. 

Titanium coating on the lower fork tubes is one of our favorite amenities because the hard surfacing protects from dings and nick and decreases stiction. A Kashima coating on the upper fork tubes also prevents binding and our testers noted a seamless transition from the plush initial action to the mid-stroke damping. Not one person complained of them being too soft, even our heaviest riders. Rigid but lenient, the Showas are a terrific blend. At Piru’s unprepped circuit and during Glen Helen’s race-day deterioration, the Kawasaki remains predictable and allows riders to push through an entire moto.

“In the air, landing, off (jump) take-offs – all over the track it doesn’t feel like it kicks,” says fast-guy Armstrong.

Handling:
Engineers went crazy in 2009 with a totally new aluminum frame that shaved 2.2 pounds off the previous design. Changes weren’t as drastic this year, but they continued to tweak the forged, cast and extruded components to tune the flex characteristics. Our riders noted a solid feel from the KX-F that made them equally comfortable in the fastest, hacked-out sections as they were in lock-to-lock infield turns.

Consistency is an important theme with the Kawasaki. In the same way that the suspension is good in small chop and hard landings, the chassis never gets out of line regardless of the situation. It might not be quicker than the YZ-F or CRF, but it’s dang close and it gives top-level predictability. Saying that a bike never does anything weird might sound insignificant, but it’s actually a huge vote of confidence.

A 23.5mm offset hustles the KX-F through corners and stoically leads the way through nasty sections. Kawasaki won the handling comparison as well as the ergonomics for its comfortable, usable rider layout and chassis. Compared to the Honda and Yamaha, the KX has more space for the pilot to work with. “It’s the most neutral bike out here,” says 5’ 9” novice rider, Garcia. “You can get on it and you feel comfortable immediately.”

The Rest:
Considering that the bike is so good with such few changes, it’s reassuring to know that many of the updates for 2010 were designed to minimize wear and increase durability – electrofusion coating on the cylinder, revised oil pump rotors, updated transmission with larger dogs on third and fourth gear and thicker crankcases. Three of our testers felt the transmission and gearing were the best in class when combined with the smooth and durable clutch. It still has a raspy exhaust note, but isn’t as bad as in previous years thanks to the new muffler. The Kawi sounds loud, but recorded 95 decibels during the stationary test.

Where didn’t it do well? Our crew is not impressed with the way Kawasaki presents itself. The green/black motif definitely has the potential to look amazing, but the KX-F is starting to feel dated. Bash really liked it, but that’s because she’s been riding Kawasakis forever. The rest of the team wants updated aesthetics and a bike that doesn’t look so haggard in only a few rides.

Braking was another area where the green 250F wasn’t extra impressive. The 250mm front and 240mm rear petal-style discs weren’t as effective at hauling the Kawi down from its significant speed. Part of that equation is the 232-lb curb weight. While getting that extra girth around the track as well as it does speaks volumes about the motor, it has the opposite effect on deceleration.

Ultimately we can barely find any room for improvement on the KX-F. It’s one of the greatest all-time 250F motocross bikes and even our complaints are only half-hearted. Riders across the spectrum of speed, weight and skill all loved the Kawasaki. It responds to punishment with increasing ability and excitement, making the KX250F one seriously fun and competitive bike. “The harder you ride that bike the better it performs,” says Sciacqua. “Everything about it was confidence-inspiring. It was great. The more I rode it, the more I loved it and the more I didn’t want to give it up.”