2020 Kawasaki KX250 Revealed

Several engine updates, new KYB suspension, and a few chassis changes.

2020 Kawasaki KX250 right profile.
Aside from the green number plates and airbox, the 2020 Kawasaki KX250 looks similar to the prior year model on the outside. However, it features a multitude of engine updates, new suspension components, and a few chassis revisions.Courtesy of Kawasaki

Kawasaki released details about its 2020 KX250, and while the 250 four-stroke motocross bike doesn't receive the complete overhaul the KX450 got last year, it features several engine updates, new suspension components, and a few chassis revisions for MY20.

2020 Kawasaki KX250 valve acuation.
Like the design found on Kawasaki’s flagship KX450 motocross bike, the KX250 now utilizes finger-follower valve actuation.Courtesy of Kawasaki

The engine now utilizes a finger-follower valve train that allows for the use of more aggressive cam profiles and enables a higher rev limit. According to Kawasaki, finger-follower valve actuation reduces valve train mass (the intake is 3.5 percent lighter and the exhaust is 4.3 percent lighter) compared to tappet-style actuation, and also lessens friction at the cam lobe. The followers have a Diamond-Like Carbon (DLC) coating to help prevent wear, and the more aggressive camshaft lobes have a chromium nitride coating for durability as well.

2020 Kawasaki KX250 engine.
The engine has a 1mm larger bore and 1.4mm less stroke.Courtesy of Kawasaki

The updated powerplant has a 1mm larger bore and 1.4mm less stroke. The wider bore allows for the use of larger valves, and the shorter stroke is claimed to help boost high-rpm performance. The intake valves have been increased from 31mm to 32mm in diameter and have 1mm higher lift, while the exhaust valves grew from 25mm to 26.5mm and have 0.4mm more lift. Straighter intake ports contribute to increased intake efficiency to help enhance performance throughout the powerband. For increased reliability and to offset the increased loads from the more aggressive cams and higher rev limit, a stronger cam chain is used and the cam-chain tensioner has been relocated to the cylinder head.

2020 Kawasaki KX250 compression.
In order to raise the compression, the piston crown has been revised.Courtesy of Kawasaki

The piston crown has been revised to increase the compression. The big end of the connecting rod now uses plain bearings instead of needle bearings for reduced mechanical loss and to help bump up the power. The exhaust system has also been revised; it’s 30mm shorter and utilizes a hydro-formed joint pipe with a reverse taper that is intended to contribute to increased top-end performance.

2020 Kawasaki KX250 throttle body diameter.
The throttle body diameter is 1mm larger and the airbox has a 60mm shorter intake funnel, both of which are designed to increase high-rpm power.Courtesy of Kawasaki

The throttle body diameter has been increased from 43mm to 44mm to flow more air, the airbox has a 60mm shorter, tapered intake funnel, and the position and angle of the upstream injector has been fine-tuned to match the airbox changes; all of which are designed to increase high-rpm power. The downstream injector was moved to the bottom of the intake duct for better throttle response as well. The repositioned intake duct increases the downdraft angle from 30 degrees to 35 degrees for an even straighter approach for intake air, which improves cylinder-filling efficiency and contributes to increased power.

2020 Kawasaki KX250 Showa Separate Function Fork and Showa shock on white background.
Replacing the Showa Separate Function Fork (SFF) and Showa shock that came on the prior year model is a KYB 48mm coil-spring fork and KYB shock.Courtesy of Kawasaki

The KX250 is now spec’d with a KYB 48mm coil-spring fork that Kawasaki claims improves action at the initial part of the stroke. The new inner tubes allow 25mm damping pistons to be used so the same damping force can be achieved with a lower internal pressure, allowing for firmer damping performance and increased riding comfort. The fork spring rate has also been increased from 9.4 N/mm to 10.0 N/mm. The bike also uses a new KYB shock; and to match with the new fork setup, it has a stiffer spring rate as well, up from 52 N/mm to 54 N/mm.

2020 Kawasaki KX250 left profile.
Chassis changes on the 2020 KX250 include lower front engine mounts, a larger 250mm rear brake disc, revised rear brake master cylinder and brake line, and new front brake pads.Courtesy of Kawasaki

Chassis changes include lower front engine mounts that have been changed from a through-bolt design to stud bolts for optimized overall frame rigidity and to enhance the shock performance. The rear brake disc size has been increased from 240mm to 250mm, and the rear brake master cylinder and brake line have been revised to reduce weight too. The 2020 KX250 now uses the same front brake pads as the 2019 KX450, which are designed to provide a more linear brake force application and better control. The color of the number plates and airbox have been changed from white to green to emulate the Monster Energy/Pro Circuit/Kawasaki racebikes as well. The 2020 Kawasaki KX250 is available now for $7,799.