HGW Performance YZ125 Billet Head & Piston Package

Unlock the full potential of your YZ125 with the HGW Performance billet head and unique piston package — a purpose-built combustion system developed specifically for high-performance motocross engines.

At the heart of the package is a unique HGW Performance piston featuring a specially designed 5° squish band, matched specifically to the geometry of our billet head. The piston and combustion chamber have been developed together to optimise squish action, combustion efficiency and burn characteristics.

The precision-machined billet head also incorporates a replaceable head-insert system, allowing different-volume inserts to be fitted to alter the compression ratio and tailor the engine’s power characteristics to suit individual requirements. This provides engine builders with the ability to fine-tune the power delivery for different tracks, riding styles, fuels and engine specifications without replacing the complete head.

Rather than simply increasing compression, the HGW Performance system is designed around controlled combustion and carefully matched piston, squish and chamber geometry.

Developed through hands-on engine development and dyno testing, this package provides a flexible foundation for extracting maximum performance from the YZ125 platform.

One head. Multiple insert options. A unique 5° squish piston. Complete control over your combustion package.

Designed together. Tested together. Built for performance.