MXA’S 2006 KX250F TEST

What a difference a year makes. After spending all of 2004 and 2005 on what were essentially clone machines, Kawasaki and Suzuki decided to go their separate ways in 2006. It isn’t a divorce of equals, though. Kawasaki’s divorce lawyer was better than Suzuki’s. How so? Suzuki will be selling the same-old 2005 RM-Z250 (with a few engine improvements), while Kawasaki dealers will get all of the engine improvements, along with a new aluminum perimeter frame, Showa suspension (front and rear), Renthal handlebars and revised bodywork.

 

If it sounds like Suzuki got the raw end of the deal in their alliance with Kawasaki, that’s not exactly true. Although the MXA wrecking crew doesn’t know what went on behind the closed doors of the Alliance board room, we do know, thanks to sources at both companies, that Kawasaki offered to share the all-new KX250F with Suzuki just like in years past. Suzuki passed on the deal. Why? The reasons are simple. (1) The Alliance, as we have known it in the past, is no more. Bike sharing is no longer a major part of the cooperative effort. (2) If Suzuki wanted the aluminum-framed RM-Z250 clone, they would reportedly have had to agree to use the new KX250F platform for at least two years. Suzuki didn’t want to. Why not? Because they have their own in-house RM-Z250 waiting in the wings for the 2007 season.

 

So, for 2006, Kawasaki has an all-new 250cc four-stroke ready to woo potential buyers into the green camp. Are they going to be successful? If the machinery has any say so, we’d say yes.

 

Q:IS KAWASAKI’S 2006 KX250F REALLY ALL-NEW?

 

A:Yes. The aluminum frame and new plastic make the KX250F look brand new from a distance, but if your dealer let you tear down the 2006 KX250F, you’d notice that the changes go beyond what you can see on the outside.

 

Q:WHAT’S CHANGED ON THE 2006 KAWASAKI KX250F?

 

A:Here’s the list of the new stuff:

(1) Aluminum frame.

(2) Plastic body work.

(3) Showa forks and shock instead of Kayaba.

(4) Cam profiles.

(5) Revised piston.

(6) Stiffer valve springs.

(7) Hotter ignition coil.

(8) Denso radiators.          

(9) Clutch fiber plates.

(10) Stiffer clutch springs.

(11) New shift drum cam.

(12) Shock linkage.

(13) Brake rotors.

 (14) Triple clamps.

 (15) Renthal handlebars.

(16) New grips.

 

Then, of course, there are the revised parts. The parts that got a massage instead of a makeover include a more efficient oil pump, revised intake and exhaust ports, higher compression ratio, surface-hardened crankshaft, revised timing and lift of the decompression system, and beefier dogs on the transmission.

 

Q:WHAT IS THE SINGLE BIGGEST DIFFERENCE BETWEEN THE 2005 AND THE 2006?

 

A:The frame and suspension. MXA test riders have always liked the power of the KX250F (even back in 2004 when it was a low-and-mid engine exclusively), but we never liked the chassis. It had a weird stinkbug feel (at least until you got Pro Circuit’s linkage), and the suspension was two years behind what Honda and Yamaha were offering.

 

Thankfully, the new aluminum perimeter frame and Showa suspension all but eliminate the handling flaws that plagued the 2005 model. Could Kawasaki have changed the linkage, put Showa suspension on the 2005 and gotten the same result? No! Those old numbers were artifacts from a bygone era of motorcycle handling. They went back to the Jeff Emig days when stand-up handling was en vogue. Those days are over. Not only did the geometry improve, but the aluminum frame also netted the KX250F a two-pound weight reduction that would have been impossible with the old steel frame.

 

Q:WHAT DOES THE 2006 ENGINE RUN LIKE?

           

A:Would you be shocked if we said that it ran like the 2005 KX250F? Don’t be. The ’06 engine feels remarkably like the ?05. As far as we’re concerned, that is a good thing. We liked the power output of the 2005 KX250F. It came on strong early and pulled hard through the middle. If it had one flaw, it was the lack of overrev (which was most pronounced on the 2004 version). The 2006 mimics the signature KX-F powerband, but it is stronger down low and revs a little further on top.

It is more powerful.

 

Q:HOW DID KAWASAKI GET THE EXTRA POWER?

           

A:Basic math tells us that most of the power improvement comes from the increased compression ratio. As any backyard tuner can tell you, that’s the quickest way to get a four-stroke to pull harder down low. At the opposite end of the spectrum, the new cam profiles help the KX250F pull further before it bangs off the rev limiter.

 

Q:IS IT FASTER THAN THE 2005 MODEL?

 

A:Absolutely. Is it night and day faster? No. Should you keep your 2005 instead of upgrading to the 2006? Absolutely not. The 2006 will beat the 2005 in a drag race every time. Also, as an added bonus, Kawasaki, in their infinite wisdom, kept all the mounts for the exhaust system the same on the new aluminum frame as on the 2005 model. Why is this such a big deal? If you purchased an expensive aftermarket exhaust system for your 2005 KX250F, it will still fit on the ’06 model (and work just as well).

 

It should be noted that past KX250F engines weren’t rock solid in the reliability department. Pumping more ponies out of the ’06 model would have been a recipe for disaster on the old lower end and cases. Kawasaki’s engineers knew this and made a zillion little reliability improvements to the KX250F running gear. Now, it should be able to handle greater loads than what it is putting out.

           

Q:WHAT’S THE MOST NOTICEABLE ASPECT OF THE 2006 KX250F?

 

A:It starts. This is the first four-stroke that starts like a two-stroke. When it’s cold, pull out the choke, kick a few times, and it starts. When it’s hot, pull in the hot start lever, kick a few times, and it starts. It’s a no-brainer. Now, if only every other manufacturer could figure out what Kawasaki did to the timing and lift of their decompression system to get the 2006 KX250F to start so easily.

 

Q:HOW DOES THE 2006 KX250F HANDLE?

 

A:The greatest compliment we can give the KX250F is that it doesn’t handle like a Kawasaki. That may sound a little harsh, but recent iterations of KX handling have felt like they were designed by a committee. Unfortunately, the committee couldn’t agree on anything, so the front end of the bike was always fighting what the back end of the bike was doing.

 

The committee must have been dissolved, because the new KX250F went straight through the rough stuff, turned better and felt solid. Can all glory be attributed to the frame geometry? No, it was a cooperative effort. It seems obvious that Kawasaki got the geometry in the ballpark and Showa fixed the rest.

 

Q:HOW GOOD IS THE SHOWA SUSPENSION?

 

A:Really good. For a lot of years Showa got a bad rap at the hands of Honda’s bad settings. That just isn’t the case anymore (as late-model Honda and Suzuki bikes have proven). With the right springs and proper valving, Showa suspension can be dreamy. And, when it comes to the KX250F, the Showa components are lightyears better than the old-fashioned parts that Kawasaki was unloading on the public in ’04 and ’05.

 

As far as suspension settings, the 2006 KX250F was a breeze. We set the sag at 100mm, fiddled with the clickers for about 30 seconds, and after that everything felt good. How good? Let’s just say the KX250F suspension can handle anything you throw at it. Fast riders, slow riders, skinny riders and heavy riders will all be at home on the KX250F.

 

Q:WHAT DID WE HATE?

 

A:The hate list:

(1) Clutch: Despite the addition of new fiber plates and stiffer clutch springs, the clutch feels weak. Invest in stiffer clutch springs if you want the clutch to last.

(2) Transmission: Kawasaki changed the shifting on the 2006 KX250F, and we have to say it wasn’t for the better. We found quite a few neutrals when downshifting from third into second.

           

Q:WHAT DID WE LIKE?

 

A:The like list:

(1) Frame. We have only good things to say about the new aluminum frame. It looks good, works well and adds a lot to the package.

(2) Engine: Making the engine more reliable is noteworthy, but the two-prong attack of more power and easier starting is a straight-up winner.

(3) Bodywork: Honda may have perfected two-tone plastic, but the black and green radiator shrouds on the KX250F, combined with the rear fender and side panels, give the Kawasaki an almost works bike look. We even think that the Buick Roadmaster port holes look cool.

(4) Handlebars. After being the last steel handlebar holdout, Kawasaki outfitted the 2006 KX250F with a set of Renthal 7/8-inch handlebars. To go along with the new handlebars, Kawasaki came up with their own proprietary grip. Modeled after a Renthal grip, the new Kawasaki grips are by far the best OEM grips made.

 

Q:WHAT DO WE REALLY THINK?

 

A:Love it! Buy it! Race it!

 

For more 2006 Bike Tests go to Top Ten Stories

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