When you think of powerful 250 four-stroke motocross bikes, Yamaha is one that likely comes to mind, and for good reason. In stock trim, its YZ250F has been praised for abundant low-end to midrange power, which is one of the key factors that makes it a favorite for many. However, although bLU cRU improved top-end power in 2021, its fuel-injected liquid-cooled DOHC four-stroke 250cc engine with a reverse cylinder head design still ranks in the bottom half of the class in terms of peak horsepower and torque.
On our in-house Dynojet 250i rear-wheel dynamometer, we documented 39.5 hp and 18.0 lb.-ft. of torque. Regardless of how it performs on the dyno, the Yamaha is still widely praised by many for its awesome power characteristics in the dirt. “The YZ250F engine is fast and has so much torque!” test rider Tanner Basso said. “It revs very quickly, so you need to shift it a lot. Still, this engine is by far the best in class.”
