who knows the inside of the 400ex carb really well?

[cals400ex]

i was i the process of changing the mainjet on the 400ex and i did not take the carb off. when i unskrewed the mainjet, the whole needle jet holder and locknut came out with it. the thing is, a piece fell out of the bottom of the carb. i did not have the whole bowl off, i just took off the 17mm bolt to get to the mainjet. the only piece that i can think of is the needle jet fell out. i guess the needle jet supports the needle along with the needle jet holder. i looked inside the carb and i did not see the needle jet. so i guess that is what fell out and i can not find it for anything. could it be anything else that fell out? i don't see any other piece missing. i don't really know what the needle jet looks like or what color it is? it may be bronze color like the other jets. any suggestions would be great. i have a picture of the carb that may help explain things, but i am not able to copy and post it in this thread.

[Glamis400ex]

I had the same thing happen. Its a little brass dealy-bob, about the size of a tic-tac. One side is flat the other is slightly rounded.

If you have a skid plate, it probably fell down there somewheres.

http://www.servicehonda.com/hard%20parts/atv/trx400ex/trx400ex%20frames%20page.htm

I know the pic sux, but look for the main jet, and the piece that fell out is #2

Glamis

[jerry-89-250R]

your clip came off the needle, that why the needle fell out, the clip should still be there, but replace it

[bpimpdaddy21]

the clip did not fall out, it was the needle jet. Anyway, anyone know what would happen if this fell out and you ran the quad without it, would it run horribly?

[cals400ex]

glamis, you are correct. that piece comes with the needle and clip. i don't need the needle, i just need the needle jet. i guess i will have to buy the whole set. jerry, you are talking about the jet needle and clip. thanks for the help.

[JOEX]

Originally posted by bpimpdaddy21
the clip did not fall out, it was the needle jet. Anyway, anyone know what would happen if this fell out and you ran the quad without it, would it run horribly?
I think it would be a tad rich:p
Happened to a friend and it wouldn't run with more than 1/4 throttle.

Joe

[jerry-89-250R]

Yes i'm talking about the jet needle and clip, the clip can't fall thru the hole the needle goes thru,the clip keeps the needle from falling thru. If you have moved the clip position you could have bent the clip as you know there very small, put a new clip on it when you put it back together. When you remove the 2 screws under the slide your clip will be there.

[cals400ex]

Originally posted by jerry-89-250R
Yes i'm talking about the jet needle and clip, the clip can't fall thru the hole the needle goes thru,the clip keeps the needle from falling thru. If you have moved the clip position you could have bent the clip as you know there very small, put a new clip on it when you put it back together. When you remove the 2 screws under the slide your clip will be there.

you are talking about the jet needle, i am talking about the needle jet. the clip did not fall out, it is still in place on the needle. the jet needle and clip you install from the top of the carb. the needle jet you install from the bottom of the carb.

by the way, which way does this needle jet go in? if one side is rounded and the other side is flat, does the rounded side face towards the bottom of the carb??

[PATTE440]

I would agree with Glamis400EX. If you have not moved the needle there should be no reason for it to just fall out. I believe it is the brass piece he explained because the very same thing happened to me. The clip on the needle is hard to get off unless you have it apart and are trying to take it off. Once you take the top off the carb you have to remove a bracket to get to the needle. With that bracket there it is almost impossible for the clip to come out.

[PATTE440]

Well I am sure there is a right way for it to go and mine has come out more then once when I was playing with jetting and I have had it in both ways and could not tell a difference. Your best bet is to contact a dealer and ask them if you want something better then a 50/50 chance.

[jerry-89-250R]

cal your talking about the needle jet "HOLDER" the threaded tube that the main jet screws into, when you said needle i thought you meant the jet needle and the clip came off, whoever changed your main jet didn't tighten up the holder when putting it back together, was the main jet still in the holder?

[cals400ex]

jerry, actually i am not talking about the holder. the needle jet goes between the needle jet holder and the bottom of the carb. i have the holder and the mainjet was skrewed right in. everything is ok but i lost the needle jet.

[jerry-89-250R]

that's what i said in the first reply, the jet needle clip came off, that's the only way the needle can fall out, did you find the needle?

[jerry-89-250R]

cal my mistake, i looked at a 300ex service manual in it they have 2 parts both called jet needle the one above the needle jet holder and the jet needle with the clip, you lost the one above the holder,the 400 manual there needle jet "the one you lost" and jet needle,

[cals400ex]

thanks jerry, you are correct now. yeah that needle jet is what i lost. i ordered a new one from the dealer and it was $30.00 :eek2: