Need some help, I have a 400EX 2002 and it has a few miles on it. It runs strong but it idles like junk. it seam to want to backfire and you can hear the carb lightly backfire also. I put in a new plug and new gas

 

USUALLY, backfiring is a lean condition. Has it run good in the past? What have you changed since the last time it ran well? There was a similar post here not that long ago, and it turned out the airfilter had been neglected, is yours clean and oiled?

 

As far as the air filter i dont have it on while i have been trying to fix it and when you say it is to lean do you mean turn the screw in on the bottom of the carb? thanks, it would be great to ride again.

 

Also i notice there are two hoses the come off the carb and run into a tee. it was not pluged into anything. is that right? item #45
http://houseofmotorcycles.bikebandit...TRAX+EX%29.asp[/L]

 

Did it first start acting up with the filter on or off? Your link didn't work for me, and I don't have a 400EX close by to look at. Most likely what you are referring to though is sme sort of overflow tube. Does it lead down to the ground? The overflows only attach at one side.

 

You take the air filter off, and it's going to make it lean which fits all the symptoms you descrived! If it still does it with the filter on, you most likely have a clogged idle jet.

 

Ya you need the air fitler on and the lid. Then adjust your valves, and through away that damn K&N air filter! Get a good foam filter your not going to loose much more than a 1/2 a horse.

 

Thanks for the info, I put the air filter back on and tryed it. no luck, i think the idle jet is the one right behind the idle screw. i turned it out a half a turn till i got to 4 turns and it still puffs out the carb and kills the motor. i pulled the jet out and it was clean. the last time it ran great was in the sand. is there a jet that might be hidding on me. I remove the main jet that is next to the float, Clean. as far as the hose, it not the one that goes to the drain. the engine runs great if you lay the hammer down I am thinking there is sand in the carb but i cant find it. again thanks for the help

This link has the layout of the carb
http://www.bikebandit.com/partsbandit/oem-parts-nav.asp

its
Honda
400EX

 

Yee Haw, I started all over and did all the steps and helps and now she pers again, thanks scooter86, Reconranger, and Cluby