KX250F

Tuned to suit the demands of race-experienced riders, the 249 cm3 liquid-cooled, 4-stroke Single’s wide powerband focuses on high-rpm performance and extends rideability way into the over-rev. Already highly acclaimed for its high output and power delivery - thanks to race-inspired tuning and factory style parts like the high-performance piston with bridged-box bottom - the 2012 KX250F takes MX engine performance to the next level with the world’s first moto cross dual injection system. The power increase – recognisable by riders of any level – is complemented by inheriting the smooth FI response feel of the 2011 model. Further engine changes offer even smoother shifting and increased durability.

The KX250F fuel injection system features dual injectors: an injector downstream of the throttle valve (where injectors are usually located on standard FI systems), and an upstream second injector close to the airbox.
Unlike the dual injection set ups found on supersport models (where the upper injector operates only part-time, providing additional fuel when necessary), the two injectors in the KX250F fuel injection system have different roles. The downstream injector is used to ensure smooth, instant response while the upstream injector is charged with providing power. As rpm and the throttle position increase, operation switches from the downstream injector to the upstream injector. (Depending on whether in a low (1st, 2nd) or high (3rd, 4th, 5th) gear, the switch is either progressive or almost instantaneous.)