2021 Honda CRF450R Dyno Test

Video By: Bert Beltran

Marking the beginning of the sixth-generation model, the 2021 Honda CRF450R is dramatically different than its predecessor. For the first time since 2012, Honda’s flagship motocross bike features a single muffler exhaust system. Other engine updates are that the cylinder head features a more centrally located exhaust port that is oval-shaped (as opposed to round on the prior model), while the camshaft layout, valve timing, and valve lift have all been revised. Some of the other most notable revisions to Big Red’s powerplant are that the airbox capacity was increased from 1.8 liters to 4.1 liters and the fuel-injector angle was changed from 60 degrees to 30 degrees.

Related: Best Motocross Bike 5th Place—2021 Honda CRF450R

As the only 450cc motocross bike to feature any sort of mechanical changes to the engine itself for 2021, we were curious to see how Big Red would perform on the dyno. After all, the CRF450R has produced the highest peak horsepower figures in the class since 2019. Sure enough, Honda retains its honor of having the most powerful motocross bike on showroom floors with 55.2 hp at 9,300 rpm and 35.1 pound-feet of torque at 7,100 rpm. In addition to cranking out the most peak horsepower and torque of all the 2021 450cc motocross bikes, the CRF450R’s power delivery is also less violent and more user-friendly than the prior-generation model. The only downside to the 2021 Honda CRF450R engine is that its EFI mapping is slightly off in stock trim and has an intermittent bog at low rpm.

“The 2021 Honda CRF450R engine has an aggressive type of power, but it is more controllable over the 2020 model. At times, there is a small hesitation in the 2,000 to 5,000 rpm range and zero to 30 percent throttle range, which is more noticeable in hotter conditions and on hard-packed, slippery terrain.” —Allan Brown