ProX Pst Kit for KTM 250SX-F '13-15/250EXC-F '14-23, 13.9:1 (77.96mm)

Bring more power, quicker throttle response, and a crisp top-end back to your motorcycle with the ProX Piston Kit 13.9:1 in the popular 77.96 mm size for the KTM 250SX-F 2013-2015 and KTM 250EXC-F 2014-2023 (also compatible with many similar 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, minimizes 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 off-the-line punch—ideal for both competitive racers and enthusiastic recreational riders.

This complete kit includes everything you need for straightforward installation: • ProX forged aluminum piston (77.96 mm) • Premium piston ring set • Steel piston pin (wrist pin) • Two circlips