Pro Circuit has introduced a Performance Engine Package for the new 2017 Honda CRF450R/RX. This all new package consists of a high-compression piston kit, camshaft and valve springs. Each part has been designed and tested to complement each other for significant engine performance gain at all RPM levels. The Pro Circuit High-Compression Piston Kit (manufactured by JE Pistons) for the 2017 CRF450R/RX provides a significant boost in low-end torque and high RPM performance. The camshaft has been designed for superior performance over the OEM cam by optimizing the valve lift profile. Used with Pro Circuit Valve Springs will ensure a valve train free of dynamic bounce. Pro Circuit Valve Springs allow the engine to run at a higher RPM without loss of valve control.