Kawasaki’s KX250 is the most heavily updated machine in the standard-model 250cc four-stroke motocross bike segment for 2025. The biggest differences from the prior-generation (2021–2024) model are chassis- and suspension-related, but its fuel-injected liquid-cooled DOHC four-stroke 249cc single-cylinder engine certainly didn’t go untouched.
Some of the many changes found in Team Green’s 250F motocross bike powerplant for 2025 are a redesigned piston, cylinder that’s tilted 5 degrees forward, a revised cylinder head shape, and a new airbox design. These updates and several others allow the KX250 engine to pump out peak figures of 39.3 hp and 18.4 lb.-ft. of torque on Dirt Rider’s in-house Dynojet 250i rear-wheel dynamometer.
“The 2025 Kawasaki KX250 engine runs better in the midrange rpm and has better roll-on power, but it may not rev quite as far as last year’s model,” test rider Allan Brown said. “This is all OK because I didn’t need it to rev further. Now, it can be shifted much sooner, and little to no clutch input is necessary to keep the engine in the powerband.”
