400 ex won't idle

[sleddog66]

Let me start by saying that I am usually over on the poo section as I ride an outlaw, but on to the problem.
A buddy of mine has a 2001 400 ex (he thinks). He just got it and it ran ok but had 2 year old gas in it. He ran it about 15 minutes and shut it off. Now he has started it back up and it will not idle itself, and really bogs out of the hole. I told him to put in fresh fuel and a new spark plug. He said it did not help. I am thinking that the pilot circuit is plugged up, or maybe even a tear in a carb boot. Before I tear into this thing, I would like to know WHAT FACTORY JETTING IS? Also does anyone have any other ideas. The machine sat in storage for 2 years, BUT it did run ok for about 15 minutes. Weird! Anyway thanks for any input. Oh ya, does this have a FCR or is there no accel pump? I guess I will see when I tear it down.

[ian0615]

I would take that tank off, get rid of the old gas, clean it out with a bit of new gas. take the carb apart all the jets out and the needle..clean the hek outta it with some carb claner and with an air comp. blow thru all the jets..every little hole in the carb. take the air/fuel screw out clean everything...get that varnish out of the fule bowl that the old gas left from sitting.
Fill the tank up with some 93 if its stock. Start with your air/fuel screw out about 2 1/2 turns..i believe thats factory, get a new spark plug. If you can get gas better than 93 i would run that for a tank just to clean it up a bit.

You should be good after that, gas does nasty things to a carb if it sits up for a long time. After i ride if i know it will be a week or so until i ride again i turn the gas off and run the bowl dry just to avoid those problems. you may have to adjust the carb a few times to get it right...while you got the carb apart take the slow jet out and put in a #40 or #42 to give it an easier start. the stock slow jet is a 38 i believe.

i hope this helps and you get it running right

[Pabst_Powered]

Stock main=148, Stock slow jet=38....as said before clean the old gas out and the carb really well, probably just gummed up from sitting

[sleddog66]

Thanks for the replies, guys. Anyone know the stock needle and clip posistion? I am at 900 ft.

Yes, gonna clean the crap out of things, just want to make sure that someone did not screw with the factory stuff too much. He has no manual.

[mineralgrey01gt]

2nd or 3rd clip is stock I think. I want to say 3rd but not 100% sure. Just clean it up well and it should be good to go. 99% of the time if the jets are stock the needle was never messed with

[PaRedneckRiders]

ya stock jets a 148 and 38
i would take the carb apart clean everything really good and let the jets soak in some cleaner (carb cleaner brake cleaner whatever even parts cleaner)
then c if u can c through them run a needle through them to make sure there is nothing blocking it and clean the tank out good
check both the boot from the airbox to the carb and from the carb to the head to c if either have dry rotted from sitting in storage prob wouldnt hurt to change the oil and oil filter since there both prob two years old and check the air filter if its like a K@N and it looks dirty clean it really good with the K@N cleaner kit (think its called a recharge kit)
but thats juz a start and some ideas of what it may b