I cant get it to stay running. The motor will turn over but it wont give any gas. Ive tried it with the choke on and it runs but not good. It makes like a weird sound. Kinda like its backfiring but not. Then when i turn off the choke it dies. It seems like its not getting any gas. Could my carb need rejeted? Ive only had this thing for a week. Its been running right untill sunday when i washed it.

 

Try draining the float bowl. If that doesn't work clean out the pilot jet.

 

lol whats the float bowl. I dont know much about carbs

 

How long does it run and sound funny? Are you letting it warm up? I think 400 ex's are cold natured things. Have you checked the main fuse under the rubber flap by the battery? ( there is an extra also) Do you have the fuel **** pointed in right direction? And believe it or not these things need gasoline; is there adequate fuel in the tank? Is the kill switch in the middle?
Start with the simple things and rule them out. Step back and have someone else stare at it and it will prob come to light......shazam Gomer.
Good luck...let us know the outcome.

 

In regard to the float bowl...you can look up how the remove/replace carbs on 400 ex on this site I think there is also a "carb 101" post (I used them to rejet) I helped a buddy r/r my carb to rejet when I got a new exhaust. In my opinion if you really dont know what a float bowl is on a carb I would advise you not to go messing with your carburator yourself. Carb problems are a freaking night mare to a newbie mechanic(I know).
The float bowl is a small bowl under carb that holds a small amout of fuel; frequently If any contamination is in the fuel it will be evident in the fuel bowl.
Hope this helps.

 

check the clip on the needle. it sounds exactly what happened to my brothers 350x when i was riding it. the clip came off and it wouldnt do anything but idle on half choke. good luck

 

Running right until you washed it??

Water in the intake charge. Unless you had the fuel cap off when you washed it [I hope not...[img]i/expressions/face-icon-small-tongue.gif[/img]].....you most likely got in the airbox.

 

I put new gas in it and it runs fine now

 

lol