Wont idle

[chewy03ex]

Hey all, was looking at some of the other posts about idle problems and I decided I needed a bit more in depth help here LOL. I know very little about this bike(its my brother in laws-im taking care of it for him for a couple years) its an 03 400 ex nothing is modded on it so far but it will not stay idling when i stop running, hot or cold it wont idle unless the choke is turned all the way to the up position. when i turn the choke handle to the halfway down position it struggles to idle and when its all the way down it wont idle at all. it sputters a bit when i decelerate but not too noticeable. what i really need to know is where do i find the idle screw on this bike, and the jet screw and which way should i turn each to try and get this bad boy going steady? i have not cleaned the carb yet, what cleaner would you reccomend to use if that is all thats needed?

thank you for your time folks :)

chewy

[GPracer2500]

Sounds like a clogged pilot circuit.

Remove the carb, disassemble, soak the jets in carburator cleaner, spray carburator cleaner (any brand will do) in every hole/orifice/surface, and blow out all the holes/orifices with compressed air.

If you've never taken a carb apart before, take your time, use quality and correctly sized screw drivers (the screw heads strip easily), and do it in a clean and organized work area. Having a service manual handy can be helpful the first time you do it.

Here's a (somewhat poor resolution) diagram of an 99'-04' 400EX carb:

http://www.servicehonda.com/hard%20parts/atv/trx400ex%2099-04/carburetor.jpg

Be aware that you usually don't need to dissassemble every last thing for proper cleaning--most of it but not quite everything.

[chewy03ex]

yeah i have never taken apart a carb before but i have a friend that can give me a hand with that. before i do take it apart though, since i havent played with the fuel/air mix at all do you think that i should attempt to correct it that way first or jump straight into the carb destruction....err cleaning LOL :P

[GPracer2500]

Originally posted by chewy03ex
yeah i have never taken apart a carb before but i have a friend that can give me a hand with that. before i do take it apart though, since i havent played with the fuel/air mix at all do you think that i should attempt to correct it that way first or jump straight into the carb destruction....err cleaning LOL :P

You can try. It's hard to reach while the carb is on the bike without a 90 degree screwdriver. The best way (the only way, really) to set the fuel mixture screw (#6 in the diagram) is while the bike is running. Also, make sure that the idle screw (#11, also known as the throttle stop screw) isn't simply turned down/out too low.

Unless someone has been monkeying with the fuel screw and has it turned in or out WAY too far, I doubt that will fix your problem. Stock setting for the fuel screw is 2 1/2 turns out from full in (lightly seated). Set the fuel screw to that and if it still doesn't idle without the choke then clean the carb.

Hope that helps.

[chewy03ex]

definitely, i pulled the carb and pulled up an electronic manual for the carb seems to be pretty easy all in all, ill let you know how it goes :)

i would try to find the idle screw first its easy to find its silver and it has grooves where you could turn it by hand but then it has a groove in the face of it for your flat head screw driver to turn it. to turn the idle up just twist it to the right a little ......but if that don't help rip the carb out and do wat that other dude said.....peace.