July 6, 2010
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MXA test rider Dennis Stapleton digs a trench in the Budds Creek dirt on the 2011 Kawasaki KX250F.

By John Basher

    So you want to know all that there is to know about the 2011 Kawasaki KX250F. I can’t blame you! The mostly new KX250F is gushing with updates and technology that haven’t been seen on a 250 four-stroke. Okay, maybe that claim is too boastful and even a bit wrong (after all, the 2010 Honda CRF250 and Suzuki RM-Z250 are already fuel-injected). Still, with several major advancements and a brief but celebrated history of producing a topnotch 250 four-stroke, Kawasaki was more than pleased to show their KX250F to the world.  On Wednesday MXA tester Dennis Stapleton and I got a taste of the bike on the famed Budds Creek National circuit.
    In the last five years, the Kawasaki KX250F has earned the distinction of being MXA‘s 250 four-stroke Shootout winner four out of five times. It’s no easy feat, considering the competitive nature among the Big Five manufacturers. Since 2006, only Honda has stolen the limelight from Kawasaki in the 250F class (doing so in 2009). Still, talk about a dynasty! The reason for Kawasaki’s success? Power placement. Although the KX250F hasn’t been the breadwinner in raw ponies (the KTM 250SXF is king), it has frequently produced the most usable powerband. In the 250F class, where the engine is most important trait, the KX250F has been a recurrent screamer.

    Now that our Budds Creek test session is over, it’s time to answer some of the questions that you might have about the 2011 KX250F. There are certain areas that I cannot and will not delve into, since MXA test rider Dennis Stapleton and I only had half of a day on the bike on an unfamiliar trac (although we have both been to Budds Creek before). For all of your lingering questions, read the upcoming 2011 KX250F test, which will be found in the pages of MXA. This is just a quick impression of the bike.

If you’re interested in finding out more about the 2011 KX250F, read on.


    A: To preface this answer, the 2011 Kawasaki KX250F received nearly 30 updates over the previous model. While there have been beaucoup improvements, there are two acronyms that really stand out among the dozens of changes. You’re already familiar with one (although you might not know it), and the other stems from years of development. DFI stands for Digital Fuel Injection, known to everyone as EFI (electronic fuel injection). DFI is marketing jargon and will be known specifically as Kawasaki’s KX250F fuel injection system if it catches on among the masses, or not if it fails (whichever comes first). Kawasaki’s DFI system uses the same size throttle body as the KX450F (43mm), but it uses a fuel injector that has 20% greater fuel injection capacity. Why? A high-revving, all-out, 250F engine needs more fuel than the 450F. And like every motocross bike’s EFI system (see it didn’t catch on with us), there is an optional fuel injection tuning kit (the KX250F kit comes with seven preset maps).

We’re happy to report that the KX250F engine and the DFI system got along quite well.


    A: Ahh, the long awaited question. SFF stands for “Separate Function Fork.” This Showa-built fork system has been developed for the purposes of easier tunability and better performance (less friction in the forks for smoother actuation). The right fork leg houses a longer and stiffer spring than a conventional fork system (after all, the spring is doing the work of two conventional fork springs), as well as a preload adjuster (obviously it has to be on the side with the spring), an air chamber, a joint rod for compression [taken from Kawasaki’s literature] and a small amount of oil for lubrication. The left fork leg houses a large piston damper with oil, an air chamber, and a sizable amount of oil. Perhaps the neatest benefit of the SFF system is that the front preload/ride height can be adjusted. One full turn of the ride height dial yields 1mm of preload. Very interesting.

The right fork leg houses a stiffer and longer spring, while the left side takes care of damping.


    A: Before last year’s 2010 KX250F was introduced rumors circulated that Kawasaki planned on outfitting the bike with electronic fuel injection. However, once the bike surfaced and a Keihin carburetor was present, it appeared that Kawasaki shelved the technology. In truth, they did. Now only a year later the KX250F comes equipped with DFI (read EFI).
    After seeing how much the EFI system changed the personality of the 2010 CRF250, I was skeptical of Kawasaki’s undertaking. The CRF250 had been transformed from having the best engine in the 250F class in 2009 to being a mostly midrange engine. EFI wassn’t the only culprit at Honda, but still MXA test riders weren’t satisfied with the outcome. Enter the 2011 KX250F. Although we have only spent a few hours riding the bike, I can confidently say that the KX250F and their DFI system seem to be mated quite well. Stapleton and I were pleased with the power output of the KX250F. I won’t speak further about the engine, as our competition will circle like turkey vultures over this report and pick apart pieces that they could use for their stories. Sad, but true. For a full and comprehensive test, right down to the dyno numbers and impressions among our plethora of test riders, you’re going to have to wait until we spend a lot more time testing the bike at a lot more tracks…then the full test will come out in the magazine.


    A: I can assure you that we definitely were not happy to see a dreaded cotter pin in the rear axle housing. Now that I got that off my chest, it’s nice that Kawasaki paid close attention to several small, but noticeable areas. They increased the amount of grip on the side of the seat cover. Kawasaki also increased the thickness of the drive chain guide to thwart off impending doom from the chain eating into the swingarm. Also on the list is decreased fork offset (23.5mm down to 22.5mm) for better cornering and increased front wheel traction. And again Kawasaki tinkered with their gear shift mechanism for better gear engagement. It’s great that the green team has focused attention on improving the shifting characteristics (even if it is for the umpteenth time).

WORCS star Ricky Dietrich was on hand to show what the underside of the ’11 KX250F looked like.


    A: The 2011 Kawasaki KX250F retails for $7299. For more information, please surf over to or visit your local Kawasaki dealer. And be sure to check out our full test on the bike in the October issue of MXA. Will the 2011 KX250F steal the show for the fifth time in six years? Time will tell.

If you decide to purchase the new KX250F, try not to follow Dennis Stapleton’s lead. Keep the rubber side down.


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