want some mods

[dirtrider420]

Want some power without going into motor.have dg pipe and uni filter. I have a 07 400ex

[ajw2685]

If you have the OEM header you can grind the welds out for some additional flow. With a slip-on and air filter you have about the most you can do without getting into it internally. As long as you re-jetted and modified your air lid or completely removed it you won't get much more.

You could do a +6 timing key easy enough for some added pep.

[sheldo]

450r carb and some tires and better shocks

[dirtrider420]

What about 450 Carb get off crf450r or trx450r and does it bolt right up

[ish416]

The 04-05 TRX450R carbs will work. The FCRs (06+) require an adapter to fit.

Don't expect much power out of an EX without getting into the engine...