The 2019 Yamaha YZ450F motocross bike is raced by Monster Energy/Yamaha Factory Racing’s Justin Barcia and Aaron Plessinger. We ran it on our in-house Dynojet dynamometer to find out how much power it makes. Yamaha’s flagship motocrosser produced 50.09 hp at 9,650 rpm and 30.78 pound-feet of torque at 7,510 rpm.