400ex dies

[trouble661]

i just installed a wb pipe on my 400ex. it dies when i pin the throttle from idle. is it too rich or too lean?. seems to run ok mid and full throttle. but then i have only ran it down the street a few times. can someone point me in the right direction on carb set up? im about 600ft above sea level and i have the midwest humidity etc.

[DantheEXman]

go down on eon the main jet. SOmeone correct me if im wrong... Also it could be the air mixture screw on the carb.

[2004TRX450R]

That would be your idle mixture is to lean. Richen up the pilot screw 1/2 to 1 turn.

[sprtrx300ex]

Are you giving the bike time to warm up?

Whats your jetting(main, needle, pilot)?

[BSTURDIVANT]

Raise the needle 1 clip position ( down on clip) and go to 3 turns open on air mixture screw from all the way in seated lightly.

If it still stumbles, go to 45 pilot 2 turns out!

DO Not richen ur mixture, its not ur main jet, its ur fuel screw or ur needle move the clip up and see if that helps also it sounds like u dont let it warm up.

[cals400ex]

whats your jetting at after you put the pipe on?

yes, i would ride it a little longer to make sure it is fully warmed up.

[trouble661]

cal.. stock jetting

[cals400ex]

i would just rejet it like we mentioned on your other posts and make sure the bike is up to full temp and let us know how it works.