DOMA Expansion Chamber for KTM EXC 250, SX 250 2011-2015

The DOMA 100363 expansion chamber is designed for KTM EXC 250, SX 250 from 2011 to 2015. On a two-stroke, the expansion chamber isn't just a pipe: its cones send back a pressure wave that fills the cylinder better at the right rpm. Its shape gives the engine its character, and a dented pipe costs power.

Key features

• Handmade in Calais, France.
• 1 mm raw steel, laser-cut parts, pressed and then welded on a jig.
• Developed on the dyno and on the track.
• Works with the stock silencer or a Doma silencer.

Specifications

• Brand: DOMA
• Manufacturer part number: 100363
• Engine: 2-stroke

Who is it for?

• Stock pipe dented or cracked after a crash.
• Looking for more response and more power.

Good to know

Competition use only: this pipe is not road-legal.

Fitting tips

1. Reuse the stock connecting O-rings if they're in good condition (not included), or fit a new exhaust gasket.
2. Offer up the pipe without forcing it, fit all the mounts, then tighten.
3. Warm up the engine and check for leaks at the joints.
4. Check the colour of the spark plug after the first few rides.

Why DOMA?

A French workshop based in Calais since 1992, Doma Racing designs and handbuilds two-stroke expansion chambers and silencers. A 125 world title in 2000 with Grant Langston and original equipment at KTM: a brand run by two-stroke enthusiasts.

Spare parts and items to plan

• Exhaust gasket : CENTAURO · ATHENA
• Spark plug : NGK 6664 · NGK 3520

Frequently asked questions

Do I need to change the silencer?
No: the pipe works with the stock silencer or a Doma silencer.

Is it road-legal?
No: for competition use on closed circuits only.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
KTM EXC 250 2015
KTM EXC 250 2014
KTM EXC 250 2013
KTM EXC 250 2012
KTM EXC 250 2011
KTM SX 250 2015
KTM SX 250 2014
KTM SX 250 2013
KTM SX 250 2012
KTM SX 250 2011