2008 Kawasaki KSF450B8F KFX 450R. Coming soon.The KFX450R ATV uses a powerplant based on Kawasaki's highly acclaimed KX450F motocross engine. With the addition of an efficient and highly-responsive 32-bit digital fuel injection system, the KFX450R's engine produces more torque in the low and medium rpm ranges for outstanding hole-shot acceleration.