2020 Kawasaki KX250

First Impression: 2020 Kawasaki KX250
Big changes equal big results on the track. Kawasaki engineers had a clear vision and made it happen.

At a quick glance you might say, “Hey, the new KX250 looks the same as last year’s, just with green number plates.” But you’d be wrong. Very wrong. The Kawasaki development team seemed to have a clear target in mind for the 2020 KX250 motor - quicker, faster, lighter and higher-reving. They also replaced the suspension with a conventional dual coil spring KYB fork and KYB shock, so all the attention wasn’t just in the engine department.

What you won’t see changed on the 2020 KX250 is that lever on the right side that you have to push down really fast to get the bike to start up. There is no e-start and while just a few years ago we all thought it was a luxury, but it is quickly becoming an expected item on modern motocross machines. Kawi has also stuck with the coupler method of changing engine maps, while others have switched to some sort of button. Also, no changes to the frame, plastics, transmission, swingarm, wheels, seat, pegs, bars and levers.

New Power | Changes

We’ll start with the biggest difference between the 2019 and 2020 bikes: the engine. At the heart of the matter is a larger bore and shorter stroke cylinder with a new piston to match. This change alone makes any motor have a faster revving character with more top-end power. But Kawi didn’t stop there. Above the cylinder is a new head that has finger-follower valve actuation, a technology borrowed from Kawasaki’s sport bikes. While this set up does add a little bit of weight to the bike overall, it lowers the mass of what is actually moving when the valves are opening and closing, which makes them quicker and easier to move. It also allows for a higher rev limit and more aggressive cam profiles. With a larger bore, the valves and valve openings themselves can also be bigger, moving more air/fuel mixture and exhaust gases per opening. 

Bigger bore and shorter stroke.

Finger follower actuation.
With this design, there is less moving mass in the valve train.

The piston has a short-skirt, box-bridged design that is supposed to be stronger and lighter than the previous piston. The compression ratio also went up from 13.4:1 to 14.2:1. The last thing that is changed inside the engine is new, low-friction plain bearings on the crankshaft pins. 

Following the trend of sorter-and-straighter-is-better, the intake tract has been straightened and shortened by a redesigned airbox and intake funnel. This is fed by a larger diameter throttle body, up to 44 mm from 43 mm. The final change to the power plant is a shorter overall exhaust, again to increase top-end power. 

The new intake track is shorter and straighter.

The left is '19. The right is the newer design.
The further head shows the larger intake of the '20 bike.

New Power | On The Track

Nearly every change made the 2020 KX250 engine all had the same goals in mind - quicker revving and more top-end power, and to put it bluntly, it worked. From the first kick, we noticed a night-and-day difference in engine character from the ‘19 machine. Over the last couple of years, the KX250 has been more of a bottom-to-mid power bike with a torquey, barky character. Now, that has all changed and the 2020 Kawi is an aggressive, snappy, high-revving machine. 

We would say that, yes, there is a little less torque and meat in the bottom-end of the power and this isn’t necessarily a motor that responds well to lugging and being lazy. But once you get into the mid, hold on to your britches. And, the bike’s rev rate is so quick that within a split second you can be in that mid- to top-end power. It’s almost like you bypass the bottom-end all together. With the stock coupler, the throttle response is on par with any bike in the class (we are hesitant to call it the best since this is the first 250F we’ve ridden this year but it might be the best) and noticeably better than the ‘19 bike. 

Fast, aggro riders will really make the most of this power and be pleasanlty rewarded for staying high in the rpm and shifting less. But, there are some things that, maybe are not cons, but things to note with this new motor. For one, the bottom end does feel a little less meaty than previous KX250s, but definitely makes up for it in the mid and top-end grunt. Two, it revs so quickly that we had to recalibrate when we should shift. At first, we were shifting too early and staying too low in the rpm and not getting the power we wanted. This is because the motor increases rpm so fast. But, once you get used to the power delivery, you end up shifting less because the bike is still making power up top. Our other tester for the day, Ricky Yorks, said that the power was slightly two-stroke like, and sort of pipey. If you let it drop too low in the rpm, or enter a turn in too high of a gear, the clutch is called into action to get it back on track. 

Normally, bikes that come with couplers have us reaching for the leaner, more aggressive coupler. Not with the KX250. We actually wanted to try the richer coupler to see what that would feel like with such an exciting, snappy motor. After spinning a few laps with the rich coupler, we actually liked both the stock and rich couplers but for different reasons. The richer coupler slows down the rev rate a little bit and sort of shifts the meat of the power back down toward the bottom/mid. It is like a step between the 2019 bike and the 2020 bike with the standard coupler. When would you use the richer coupler? Riding at Castillo Ranch, there were patches of dry loose dirt and slick muddy dirt randomly spaced on a track that was mostly prepped perfectly, and with the black coupler slowing the rev rate down a few notches, it was easier to maintain consistent traction throughout the track. That being said, we still preferred the stock coupler overall because of the instant power. 

New Suspension/Chassis | Changes

An all-new KYB 48 mm fork is on the front of the bike while a new KYB shock is on the back, and we are very happy that Showa SFF fork is long gone. The inner tubes are bigger and allow for 25 mm damping pistons to be used, which are the same size as what’s in Tomac’s KYB fork. The outer tubes are Kashima coated and the spring rates are stiffer overall (9.4N/mm to 10.0N/mm). The new shock also has Kashima coating on the outside, a stiffer spring rate (52N/mm to 54N/mm), and new linkage for a longer shock stroke. 

As far as chassis changes go for 2020 there are new lower front engine mounts that use stud bolts instead of through bolts, which is supposed to help offer more comfort. There are also some changes to the brakes. The front brake gets new pads that are supposed to have a more linear brake feel and the rear disk went up fro 240mm to 250mm and the caliper is the same unit used on the KX450, which is lighter. 

New pad material up front.
Larger rotor and new caliper out back.

New Suspension/Chassis | On The Track

Just as the engine surprised us with how different it felt, the same thing applies to the suspension. We’re pretty sure there aren’t too many fans of the SFF fork. It is hard to set up and hard to get a good balance of comfort and performance. But with this new KYB fork, we were comfortable from the first jump on the track. To be fair, Castillo didn’t get choppy or chunky since there weren’t that many riders on it, but overall, we got a good feel for the new suspension. 

Braking is very controlled, front and rear.

Ricky, being faster, would prefer an overall stiffer set up but he was happy with the stock setting and praised the comfort over the previous SFF. I, on the other hand, still like the fork much, much better, but I went two clicks softer on compression to get the fork to start to move easier and sink a little lower in the stroke on corner entry. The overall action of the fork is plush but not soft or hollow feeling. There is proper hold-up but I didn’t notice slap downs or hard hits being transferred to my hands. One of the biggest boosts in confidence a bike can give a rider is being composed when the rider messes up by over-jumping or coming up short, and this bike was just that. We could trust the suspension to handle pretty much everything that we could throw at it, including our talent running short. 

Overall, the handling of the bike very well balanced. We don’t think you can really classify the KX250 as only a rear-end or front-end steering bike, where in the past, it was easily described as favoring rear-end steering riders. Ricky is a rear-end biased steerer while I prefer to use the front more and have more weight forward than back. And we were both able to get the KX to turn for us well (Ricky more so than I, though). Ricky’s comments about the handling were that he found it to be very nimble and quick turning, even compared to last years bike.

On the other hand, I was having a little issue with initiating a corner, similar to what I’ve felt in the past on Kawasaki’s. Once in the turn, be it a rut or berm, I found the Kawi to be planted and stable, but just getting the initial lean-in took some effort. The KYB engineer at the intro simply added more preload on the shock spring to get the rear up a little higher which really helped with the cornering. For some reason, Kawasaki didn’t focus on specific sag numbers at this intro, which they have in the past. They just really went by feel and our feedback. Once the bike was balanced to my liking, I was much more confident in turning the KX, though I wouldn’t say it is as sharp turning as Suzukis or Hondas (at least the 2019s). 

Last Word

It is a new dawn for the Kawasaki KX250. We are extremely pleased to see that the changes made on paper translate to very noticeable changes on the track because that isn’t always the case. One thing that was said in the tech presentation, though, we don’t necessarily agree with. They made the case that with the new, more aggressive, harder-hitting motor and the stiffer suspension settings, this new KX250 is really for the race-experienced rider. I don’t dispute that, but I would like to add that I think this bike is ALSO for a less experienced or non-race focused rider as well. What makes the new engine character good for a racer is the same thing that makes it fun and exciting to ride for an average Joe. At the end of the day, we’ll have to wait and see how this bike stacks up to its 2020 competition but based on today’s ride the KX250 is swinging for the fences. 

Sweet championship bikes on display at the tech presentation.


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Kawasaki KX250
Model Year
Engine Size
Engine Type
Engine Displacement
Bore x Stroke
78.0 x 52.2 mm
Compression Ratio
Fuel System
DFI® w/Keihin 44mm Throttle Body & Dual Injectors
Digital DC CDI
Final Drive
Suspension Front
48mm Inverted, Coilspring Fork with XX-Position Compression and XX Position Rebound Damping Adjustmen
Suspension Rear
Uni-Trak® w/ Adjustable Preload, XX Position (Low Speed)/ XX Turn Stepless (High Speed) Compression Damping Adjustment, XX Position Rebound Damping Adjustment
Brakes Front
Semi-Floating 270mm Disc
Brakes Rear
240mm Disc
Tires Front
Tires Rear
Overall Length
Overall Width
Overall Height
Seat Height
37.3 in.
58.3 in.
Ground Clearance
13.1 in.
28.6°/5.1 in.
Fuel Capacity
1.7 gal.
Curb Weight
231.4 lb.
More Info
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