An Ultra-Competitive Kawasaki
Photos by Drew Ruiz/Trevor Hunter
Kawasaki and the KX250F has been a long time dominator of the 250 class in motocross and supercross with their solid base being virtually perfected by the Pro Circuit Racing Team. In fact, the Kawasaki KX250 (yes the “F” was dropped from the name in 2019) is the winningest 250cc machine since 2004. Despite those achievements, they seemed somewhat irrelevant last year when riding the 2019 model. Though competitive, the motor would sign off early in the higher RPM’s. Additionally the Showa SFF Fork left us searching for the perfect setting. This year on the other hand, the engineers at Kawasaki are ready to make the competition see green with envy. They dumped a host of refinements into their KX250 and invited us out to Castillo Ranch in central California to put them to the test.
Upon arrival to the event venue at the beautiful Pence Vineyard in Buelton, California, we were introduced to the newest KX as well as some of its championship-winning predecessors. On the outside the bike looks the same as it has the past few years other than the bold new green plastics. The Kawi technicians informed us on the updates to the 2020 machine including major revisions to the engine, suspension, chassis, and brakes. To be specific, a new 44mm throttle body (over last year’s 43mm) was added as well as a 50mm shorter and more direct air intake funnel. To accompany these changes, the airbox is now fully ventilated on both sides, something that was only one-sided in last years model. A higher compression piston has also been paired with larger intake and exhaust valves for a higher revving characteristic. New DLC-coated finger follower actuators are also present in the new KX250 and are the same ones used in the ZX-10 sport bike. Suspension components are all new for the 2020 machine with KYB coil-spring components outfitting both ends, ditching the Showa components used in years past. The engine mounts have been changed to stud bolts rather than through bolts and are said to improve on-track chassis feel. The green machine boasts a new rear brake master cylinder and a 250mm rear brake disc, the largest rear disc in the class, along with updated front brake pads. This motocross racer has been revised, with help from Kawasaki’s World Superbike development team, to develop more power in the mid to upper RPM ranges and is geared specifically towards the “race-experienced rider”.
The 250cc class is a big contest with all the manufacturers racing to get the most ponies out of their bike and Kawasaki went at it implementing some of their street bike technology into the motor. Right away we noticed the KX, like many other modern day 250F’s, liked to be screamed around the track. It is a top-end heavy power delivery, and with developers coming from the street bike side of things, this is no surprise as road racer’s rev to the moon. The Kawi’s bottom-mid end power was about average, better than some but still lacking compared to others. Where the bike really comes to life is in the top end. The further the bike revved, the more power you got out of it. Unfortunately, the track at Castillo Ranch is a bit tight and didn’t let our riders experience all that the top end has to offer. For SoCal folks, it’s a bit like Gorman with a narrow track, a lot of corners, and mostly hard pack dirt.
Back again for 2020 is Kawasaki’s three coupler system with standard (green), aggressive (white), and mellow (black) couplers. Both of our riders felt that the standard and aggressive couplers were ideal when racing around the central Cali circuit. The standard coupler provided a smoother bottom end, eventually leading into a strong mid range and continually building top end. The aggressive coupler; however, had more overall power while giving the bottom-mid some life while taking away from the overrev a bit. On this tight track, both felt the aggressive coupler aided the machine. Shifting felt smooth and precise, and gearing wasn’t much of an issue, though our riders fit nicely in the target weight for the small bore four-stroke. On a deeper track, experimenting with a larger rear sprocket could be in the cards for the green machine. Clutch actuation was nice and smooth with no fading throughout the day.
Onto the suspension side of things, the Kawi folks had our guys in the 105mm race sag range. When the sag was off, the bike suffered in handling; however, when the sag was right, it served as a good package. The track didn’t have much in terms of rough real estate, but in the small sample size that we got, we feel the bike is in the right direction. Due to Kawasaki’s race inspired, aggressive setup for 2020, the bike is a bit stiff. Our smaller rider softened up the low speed compression front and rear a few clicks to get some added comfort in the chop. Our bigger test rider sped up the rebound in the fork one click to find a plusher ride in the initial part of the stroke.
In our past experience, the KX 250 had the ability to carve corners and this year’s bike stays close to that standard. We felt it gave up a slight amount in the turning department in order to gain a little stability, but overall is a positive. The chassis felt compliant with the terrain and wasn’t too stiff riding like a bucking bronco. Brakes felt good, with both front and rear providing plenty of stopping power without being too touchy. Our taller rider tried the footpegs in the lower mounts and liked having his lower body lower on the bike allowing him to get a better grip and feel for it.
Overall, the 2020 KX250 is an improvement over the previous generation thumper, though it’s still missing a critical magic button (2021?!?). A strong motor package paired with good suspension and a solid chassis has this bike jumping into the deep end with the rest of the competition. Will it be enough to take top honors? We can’t say much yet, but we’ll continue to ride this bike around more familiar tracks to get a better understanding on how the bike truly performs under our “normal” conditions. As always, stay tuned to the site and our social media channels for more regular updates.
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