2011 Kawasaki KX250F announced
New fork system separates spring and damping functions
The 2011 Kawasaki KX250F uses a new Separate Function Fork system from Showa that splits spring and damping functions between each leg. According to Kawasaki, the Separate Function Fork reduces friction by 25%, lowers weight and is easier to adjust than conventional forks.
The right leg handles spring functions, using a larger main spring/rod assembly than traditional forks, and a small amount of oil for lubrication. A blue-anodized adjuster on the right leg’s cap adjusts the spring preload.
Meanwhile, the left leg handles damping functions, and has no springs. Instead, it contains only a cartridge damper assembly and fork oil. Rebound and compression are adjustable.
The inner tubes of both fork legs are coated with titanium nitride to further reduce friction. Kawasaki also reduced the fork offset by one millimeter with the aim of improving handling and steering response. The rear shock has also been updated with revised damping settings.
The KX250F also receives the battery-less Digital Fuel Injection system similar to the one introduced in the 2009 KX450F. According to Kawasaki, the DFI system automatically adjusts to suit track and climate conditions to offer consistent fuel metering through rough riding such as during jumps and whoops. The system does not use a battery, instead relying on power generated by the kickstarter.
Kawasaki also offers an optional ECU setting tool with a selection of different data maps. The tool also allows for fine tuning a custom map for fuel injection and ignition timing. A data logger records up to six hours of information.
The engine uses a new bridged-box-bottom piston design, introduced in the 2010 KX450F. A new stainless steel exhaust system with a longer headpipe limits noise levesl to 94 dbA to meet new AMA Pro Racing rules.
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