Fuel-injected 449 cm3 liquid-cooled, 4-stroke Single delivers hard-hitting power from low- through high-rpm. The broad powerband and responsive throttle offer a broad spread of torquey response that enables racers to get on the gas and go even from down low. Race-inspired tuning and parts like the high-performance bridged-box bottom piston (a mass-production first when introduced on the 2010 KX450F) ensure top-level performance right out of the box. For 2016, an offset cylinder and numerous changes to the intake system offer even more power, the new exhaust system is quieter, and a new accessory KX FI Controller enables map calibration without a PC. Like the chassis, the engine benefits from significant weight savings, with the engine group components weighing almost 2 kg less!