Designed to be an enduro racebike and aggressive trailbike, the Yamaha WR450F is heavily based on the YZ450F. Following in the footsteps of the motocrosser in terms of updates, the 2021 WR450F enjoys many of the same changes the YZ450F was granted last year. Engine-wise, this includes a more compact cylinder head, 1.5mm-longer connecting rod, and larger-diameter header pipe just to name a few.
The WR450F is also spec’d with some enduro-specific features that alter its engine performance, characteristics, and output compared to the YZ450F and YZ450FX such as an EPA-compliant spark arrestor-type muffler and off-road-specific ECU tuning that is also EPA-compliant. How did the all-new WR450F perform on our in-house dyno? With a Dunlop D404 street tire on the rear wheel, it cranked out 48.9 hp at 9,000 rpm and 31.8 pound-feet at 7,200 rpm.