The SXS cylinder heads with variable combustion chamber are a must-have for any racer and offer the following properties:

• Cylinder head separate from combustion chamber
• Easy modification of the engine characteristic by changing the combustion chamber insert (e.g., from Motocross to Enduro setting)
• No need to replace the entire cylinder head in case of wear; only the insert needs to be replaced
• The aluminum alloys provide improved heat dissipation and thus improved performance gains

To boost your motorcycle's performance even further, we recommend a combination of the factory cylinder heads with the following parts:

• SXS spark plug
• SXS digital box
• factory exhaust system

IMPORTANT:

The carburetor jetting must be adjusted to the selected combustion chamber insert and your vehicle model year (e.g. selected combustion chamber insert = Motocross type; vehicle = 250 EXC model year 09; carburetor jetting to be selected = 250 SX model year 09). The carburetor jettings for models 250 and 300 are identical. When using the "EXTREM" combustion chamber insert, always select the SX carburetor jetting for your vehicle's model year. More information on the carburetor jetting can be obtained from your authorized dealer.