FMF Fatty Pipe Expansion Chamber — KTM 250/300 SX / EXC / MXC / XC / XC-W 2003–2010

A tuned expansion chamber that reshapes the power curve — sharper throttle response and a broader spread of usable power.

Fits: KTM 250/300 SX / EXC / MXC / XC / XC-W 2003–2010.

Why riders pick it:

• Low-end and midrange focused chamber tuning for broad, tractable power delivery
• Ideal for tight trails and technical terrain where snappy top-end power isn't the priority
• Works with your stock silencer or any FMF 2-stroke silencer
• Direct bolt-on installation, no tuning required

⚠️ For closed-course competition / off-road use only — not legal for street use in some states. Confirm your local regulations.

Not sure it fits your bike? Send us your year and model and we'll confirm.