2018 Kawasaki KX250F Review
The 2018 Kawasaki KX250F is the second year of the brand’s newest generation quarter liter motocross bike. The 2017 model was an all-new machine, so Kawasaki sought to improve on their newest generation bike by making refinements to the engine and suspension. The changes made to the engine were implemented to try and improve the power and torque throughout the rev range while the new suspension settings were aimed at better overall compliance.
The changes made to the engine include a new throttle body with a less vertical injector mounting angle, a new fuel pump, a revised intake duct and shorter intake funnel, a new cylinder head design, a new intake camshaft, revised ECU settings, and a new header pipe.
The changes to the suspension were made in both the front and rear of the bike. Up front, the Showa Separate Function Fork (SFF) has a softer spring and added preload in the right fork while the left fork receives a new compression shim setting, a new rebound shim setting, and a new BCV shim setting. The rear shock changes are a new rebound shim setting, compression shim setting, and new plug-bolt setting.
After my first couple of laps, it became very apparent that the KX250F engine has a linear powerband. I didn’t notice any part of the RPM range that I felt was lacking or left me wanting more in one area or another. Because of this, I could ride the bike, for the most part, however I wanted. I could lug it down low in the RPMs and short shift it, or I could keep it singing and bouncing off the rev limiter. The ability to lug the engine was very nice for me, especially because I have spent quite a bit of time lately testing 450cc four-strokes. As a result, I have become used to being able to lug the bike and ride it as I please. The KX250F offers this same luxury.
There were a few times when I kept the bike too low in the RPMs and a slip or pop of the clutch was necessary. In these instances, I did so and the bike immediately got back on the pipe. Also, I rode with the white (aggressive) coupler because the dirt at Cahuilla was soft and sandy, so I wanted to get every bit of power out of it that I could. I look forward to testing this coupler along with the other two options in a variety of track conditions to see if this map works equally well on hard packed terrain, too. Also, shifting the KX250F was smooth and didn’t require a big effort on my part to grab a shift, even under a load.
Moving on to the suspension, the front fork has a somewhat firm feel that is mostly noticeable in the beginning of the stroke - almost as if it's not very progressive in this area. The fork handled braking bumps and obstacles well, especially the harder landings. I am eager to try and soften the initial part of the stroke more to my liking. However, with that being said, the fork soaked up braking bumps and hard landings just fine and I didn’t feel any negative feedback in my hands. The track didn’t get too rough at Cahuilla during our test day, so it will be interesting to see how this fork performs when faced with a rougher track. For the rear shock, I started riding at the beginning of the day with 100mm of sag, which worked alright, but I wanted the rear to squat a little more and have less weight on the front end. The Kawasaki technician working with me for the day, Casey Stewart, adjusted the sag to 104mm, which proved to be the right move as the bike felt more balanced after we made this change.
The handling of the KX250F can best be described as nimble. I felt like I could put the bike wherever I wanted with only the slightest bit of input. This feeling is noticeable in several parts of the track, especially when entering ruts in tight corners. I was able to point the bike in the direction I wanted and it complied every time. Also, the bike feels very skinny between your legs as the plastics are tucked in nicely on each side.
After a day of spinning laps on the 2018 Kawasaki KX250F, I was very impressed with the bike overall. The chassis is nimble and easy to move around on while the engine offers a “no surprises” type of powerband that is plentiful, yet predictable. The suspension is firm and absorbs all of the big impacts well, but also soaks up the small bumps, too. I think it will be even better once we get the initial part of the stroke to move more. I look forward to spending more time on this bike prior to our 250F MX Shootout to see how it performs on different tracks and different types of dirt.