For 2009, Kawasaki becomes the third Japanese manufacturer to offer a fuel-injected open-class motocrosser. The all-new KX450F uses essentially the same Keihin EFI system as the Honda CRF450R and Suzuki RM-Z450, with a 43mm throttle body, 12-hole injector and progressive, two-shaft throttle link that gives quicker response beyond 3/8-turn. Like the CRF, the KX gets by with a plastic gas tank instead of metal as on the RM-Z. Naturally with EFI, jetting changes are a thing of the past. Moreover, with no float bowl there are no worries of fuel sloshing causing bogging; and with no breather hoses no gas spills out, which is good for fuel economy and the environment. An optional setting "tool" with a diagnostic port bolts behind the front numberplate to allow further EFI tuning and data acquisition via a laptop computer.