DK Offroad

Last year's version blew the doors off with all-new fuel injection, but for 2010 the KX450F isn't changed as radically. This burly beast is only refined for the new year with adjustments you can't see from the outside. Inside the motor is a new bridged-box piston. It shaves seven grams and has a 6mm-shorter skirt. Kawi claims it increases performance at the top of the rev selection. The intake cam timing is advanced two degrees and ECU settings are tweaked. Kawi says the piston design has been proven through use in the race staff bikes along with a wedge-shaped crank which is already in use.