ProX Piston Kit for KTM250SX-F'13-15/250EXC-F'14-23 13.9:1 (77.97mm)

Restore more power, quicker throttle response, and a crisp top-end to your motorcycle with the ProX Piston Kit 13.9:1 in stock size (77.97 mm) for the KTM 250SX-F 2013-2015 and KTM 250EXC-F 2014-2023 (and often also compatible with equivalent Husqvarna FE 250 models from that era).

This premium high-compression piston kit from ProX Racing Parts is an excellent upgrade or perfect replacement for a worn-out original piston. ProX pistons are manufactured from premium forged aluminum on state-of-the-art CNC machines, with a special anti-friction coating on the skirt. This reduces friction, improves heat dissipation, lowers wear, and extends service life – even under the harsh conditions of motocross and enduro.

The 13.9:1 compression ratio (slightly higher than stock) delivers noticeable horsepower gains, especially in the mid-range and high-RPM bands, without requiring a full engine overhaul. The flat-top piston with an optimized combustion chamber ensures efficient combustion, better throttle response, and extra snap out of corners – ideal for both competitive riders and enthusiastic recreational riders.

This complete kit includes everything you need for straightforward installation: • ProX forged aluminum piston (77.97 mm) • Premium piston ring set • Steel piston pin (wrist pin) • Two circlips