just got a 400ex for my old yfz450

[turboed]

yfz needed a crank,anyway my question is do i need to rejet the ex
,it has a gutted stock pipe and k&n with outerwear and lid is on,runs good but want to be safe.,this is a 2002 400ex.

[trailrider894]

is this a question??? but yeah man the 400ex is the bomb of performance quadS!!! by the far the best handling out there that i've ridden. and there mod ablility is amazing!!!! i'll never own anything else!!!

[maxamillion]

It wouldnt hurt to go up a few sizes on the main. I would do a 152M and then throw in a 42 pilot while your at it.

[deathman53]

I hope you know that a gutted stock pipe isn't really a good mod. You may think its more powerful, because of the noise. But in reality, you probably lost power, its no better than a cobra pipe and probably almost as loud.

[turboed]

thank you guys i'm looking for a pipe also since i got it like that and tomorrow i'm getting the jets

[Yippie-Ki-Yay]

Originally posted by turboed
thank you guys i'm looking for a pipe also since i got it like that and tomorrow i'm getting the jets

Well if it helps i can give you some ideas. Main pipes i tend to see on the ex are HMF's, Sparks, And White Brothers. If your really short on cash, the lexx slip on is great.

Hope this helps.

[motox92]

I just bought a 2002 400ex, cant wait to start modding it. Get rid of that GUTTED PIPE.