whats wrong

[03400exrider]

i have a 2003 400ex and i just got it out of the shop for smokin and backfiring when you try to crank it and when i got it out it ran for a while and now its doing it again could it be the carby?

[BEAVER.989]

My best guess... They cleaned your carb, which worked fine until it sucked in more debris from a dirty fuel tank.

Drain the tank and clean the carb. See what ya get.

... Of course, I could also be way off.

[03400exrider]

ok thanks dude they put a carb kit in it and i gues it just got dirt and stuff in it but if so i have the stock air filter in it is that ok? it is a sponge filter

[BEAVER.989]

Foam filters are great, provided they are cleaned and well oiled.

Just to be sure we're on the same page... You said your quad wasn't running right. You took it in and afterwards it ran right for awhile and is now acting up agian, correct?

If so, then I think my assumption would be correct. If I misunderstood you and it came back from the shop still not running right, then it could be a completely different issue altogether.

[03400exrider]

yeah i took it in and when i got it back and it was runnin like new and then when i got off the trails i sprayed it off and cleaned it and dried it off put it up and when i went crank it wouldnt start and it kept backfiring and thats all it will do and its blowin smoke like crazy

[BEAVER.989]

Hmmm. It ran great until you wahed it? I'm wondering if you're getting water in the intake, or something...

[03400exrider]

see thats what i thought so i checked and the airbox has a lid on it so it was all dry but the hose that runs from the box to the carb had a good bit of dirt in it and the clear intake tube had some in it to so i cleaned it out and cleaned my airfilter and put it all back together so when i get home i think im gonna check out my carb

[BEAVER.989]

Definately clean the airboot. The fact that you have dirt in there suggests that it's time to replace the filter and/or be certain that it's connected correctly. It needs to be airtight.

Drain the float bowl. I believe you'll need a 17mm socket. Depending upon how much dirt was ingested, you may even have to clean out your jets.

[03400exrider]

but i just had it replaced about 1 month ago would really need replaced that quick and yeah im gonna do all that because this is the second time its done this in 1 months

[BEAVER.989]

I guess it all depends on the conditions you ride in and exactly how much riding you actually do in a month.

[2001trx400ex]

clean your carb with carb cleaner and try different jets to

[Snipe]

Are you letting the air filter dry completely before you run the bike or re install it? If not my be getting water spray in the intake it will affect how the bike runs even causing backfire in the carb.

[02' trx400ex]

try changing your pilot and main jets.