The 2018 Kawasaki KX250F motorcycle returns for 2018 with a list of enhancements to keep the KX250F on top as the single-most dominant motocross bike of the last decade. The 2018 model offers an updated engine for an improved torque feeling throughout the rpm range, as well as improved holeshot performance. The KX250F still features a lightweight, slim and rigid chassis, but now features revised suspension to deliver improved bump absorption and suspension action. These improvements all mean one thing: faster lap times—the 2018 Kawasaki KX250F was found to have significantly faster lap times on the Kawasaki test track compared to the 2017 model.
- Improved power and torque throughout the rev range
- Improved suspension settings for better compliance, resulting in quicker lap times. Up front you’ll find revised Showa 48mm Separate Function Front Forks (SFF Type 2) with works-style internal construction that locates its damping assembly in the left fork tube and a spring in the right. For 2018, revised settings contribute to greater precision over braking bumps and through corners.
- The 2018 Uni-Trak rear suspension with Showa shock features revised settings, new for 2018. These changes contribute to improved ride feel, traction, and increased rear-end feedback.
- There is a new throttle body and fuel injector angle, for increased torque feeling throughout rpm range.
- A new fuel pump features increased output pressure.
- The intake boot has been reconfigured. The intake path has been revised with a shorter intake funnel and redesigned duct.
- The engine gets a new intake camshaft, intake valve timing has also been advanced, new cylinder head with revised intake tract and new compression ratio (13.4:1).
- The exhaust header is longer and larger tubing diameter further increasing torque and power output, while retaining the resonator chamber.Riders will feel more power from low to high rpm, and experience improved over-rev characteristics.
- The dual-injector fuel injection system of the KX250F is a key component to its performance; the 2012 KX250F was the world’s first production motocross bike to use such a system. Unlike a standard fuel injection system, which uses one injector downstream of the throttle valve, the system on the KX250F motorcycle uses a second, upstream injector located close to the airbox. The downstream injector is used to help ensure smooth, instant response featuring a finer atomization with more holes in the injector itself. The downstream injector creates that stronger low-to-mid range power and quick throttle response, while the upstream injector is charged with providing top-end power.
As rpm and throttle position increase, primary 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 transition is gradual and seamless. The upstream injector’s greater distance from the combustion chamber gives the fuel particles and intake air more time to mix, as well as allowing the mixture to cool before entering the combustion chamber, both of which contribute to more efficient filling, and ultimately more power.