2020 Kawasaki KX250 Revealed

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.

Related: 2019 Kawasaki KX450 First Ride Review

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.

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.

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.

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.

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.

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.