After receiving a full “backward” engine redesign for 2014, the YZ250F has benefited from periodic updates and carries on apace for 2018. A word about this backward business: Following in the tire tracks of the YZ450F, the 250cc DOHC engine’s intake was repositioned at the front and its exhaust moved to the rear with the cylinder and head also inclined rearward for better mass centralization. Along with sharper chassis geometry, this transformed the lazy-steering previous model into a terrier, capable of attacking inside lines as well as railing around the outside with equal zeal.
The YZ250F also gained electronic fuel injection with a big 44mm throttle body in its transformation. Importantly, an accessory GYTR power tuner lets riders quickly tailor EFI and ignition maps to their personal preferences, though this must be done in the pits and not in real time aboard the bike. Fully adjustable KYB suspenders offer more than a foot of travel at both ends, and the fork features speed-sensitive valving that adapts damping rates—mechanically, not electronically like some premium superbikes—to both speed and terrain.
Likes: Meaty powerband, nice-handling balance
Dislikes: Annoying fuel-cap access via a flip-up seat panel, loud intake noise
Verdict: All the good stuff, with four AMA MX championships to prove it
