Kawasaki KX250F KXF250 2021-2024 Service Manual

2021 marked a genuine turning point for the KX250 — Cycle World called it a major overhaul, and Motocross Action's testing backs that up: after two years developing the new aluminum twin-spar frame on the KX450, Kawasaki dropped its 250 engine into that same chassis for 2021, alongside a substantially revised powerplant. Engineers reworked the head, camshafts, piston, crank, and clutch, paired with new mapping and a Renthal fat handlebar for a genuinely different feel on track.

The 249cc liquid-cooled DOHC four-stroke single makes a claimed 45-46 hp, delivered through Kawasaki's dual fuel-injector system — the KX250 was the first mass-production motocrosser to use it, with one injector positioned downstream of the throttle valve for smooth low-rpm response and a second upstream near the airbox for stronger peak power at high rpm. A fully adjustable 48mm inverted Showa fork and Uni-Trak rear shock with dual-range compression damping round out the suspension, backed by competition-grade petal disc brakes and 13.2 inches of ground clearance.

Kawasaki made no major mechanical changes for 2024, closing out this generation with cosmetic updates only — a bold new shroud graphic, an all-green seat cover, and green fork guards replacing the prior black trim. By 2024, four years of race-calibration feedback had produced what testers considered the most refined, consistent fuel and ignition mapping of the post-2021 engine architecture, though the bike's genuinely loud, high-strung exhaust note and top-end rattle remained persistent talking points among testers. Weight comes in around 228 lbs. This generation was replaced by a redesigned KX250 for 2025.

This factory service manual covers the procedures, torque specs, and diagrams needed to keep a 2021-2024 KX250 running the way it was built to.