The Apex Technical Innovations billet cylinder head offers a two piece design made of 6061 aluminum alloy. The two piece design allows for interchangeable combustion chambers (domes) to suit the power characteristics of any riding style. “Best bolt-on mod on the market.”

Fits the following models:

300 XC-W 2017+
300 XC-W TPI 2017+
300 XC 2017+
300 XC TPI 2017+
TE 300 2017+
TE 300i 2017+
TX 300 2017+
TX 300i 2017+
EC 300 2021+
EX 300 2021+

The SX dome gives a big midrange boost with more power throughout the power curve. If you’re looking for the pulling power of a 450f while maintaining the two stroke fun factor, this is the dome for you. It is best suited to tight tracks with lots of jumps out of corners, motocross conversions, and for those at high altitude. This dome requires 93 octane from 0-2000ft and is 91 octane safe over 2000ft.

The MXC dome comes on the pipe sooner, gives a smooth midrange pull, greatly improves top end power, and extends overrev. This dome works best on fast, flowing tracks, fire roads, and in the desert. This dome is 91 octane safe at all altitudes.

The XC dome is designed to smooth out the power curve and make the bike more tractable in the woods. It will improve low end throttle response, add torque, and help reduce stalling. This dome is 91 octane safe at all altitudes.

For fuel injected models, these domes are designed to work with the OEM ECU maps. We highly recommend getting the most recent OEM updated map for your bike, which can be supplied by your local dealership.

All three domes feature combustion chambers that are fully optimized (compression ratio and MSV) for their specific riding conditions and have a nominal squish clearance of 0.050”.

Apex Cylinder Head Individual Domes