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. Designed with harescrambles in mind, this dome works best flowing tracks and trails, 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 extreme enduro conditions. It will improve low end throttle response, add torque, and help reduce stalling. This dome is 91 octane safe at all altitudes.

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”.

The OEM cylinder head leaves a lot to be desired (see our FAQ), and it’s large squish clearance can lead to jetting woes, detonation, poor fuel economy and throttle response, and less power. The Apex Technical Innovations head solves all of these issues while giving you an increase in performance where you need it most.

All three of our standard domes are designed to run on pump gas, but we can accommodate requests for race gas domes or for those at high altitude. Finally, the two piece design allows for higher coolant volume and flow was specifically designed to remove heat as efficiently as possible. Combine this with the higher thermal conductivity of billet 6061 aluminum vs billet 7075 aluminum and cast aluminum alloys, and you have a recipe for a powerful, usable, and reliable engine.

Custom domes available, email/message for details

Note: this kit does not contain OEM head gaskets.