The Kawasaki KX450F has built a reputation in the past couple years as having a monster 450 MX motor. That's still the case with the 2008 Kwakker, but it seems as though every year the rev limit gets shorter.
Watch the video and then see how the Kawasaki KX450F did in the MotorcycleUSA.com 450 Motocross Shootout at www.motorcycle-usa.com