400ex Carb Experts... i got problems.

[wohorsy96]

ok i bought an 02 400ex from a buddy of mine and when i bought it he said not to mess with the choke when starting, or hit the gas to fire it up because this would flood the bike and probably mess up the spark plug. Well tryin to start the bike today i hit the gas and of course it wouldnt start. I did get it started however, by push starting after pulling the plug and cleaning it, which was black and sooty but not wet. The bike has an fmf pipe and twin air ( or something like that) filter. The carb has been jetted.Heres my question....

- is the bike running way to rich? i can never get it to just idle for long periods of time. How do i adjust this if it is? The Main jet?

Thanks for any help.

I would check the piloet jet b/c that's wut controls the fuel under idle and 1/8 throttle if it is a 38 which is stock I would try to go to a 42 which most people run.

[wohorsy96]

Thanks, should i get that from the stealership, or order a kit? i hear alot of good things about dynojet... where is a good place to get these kits? btw how do it tell what size is in there, is it written on the pilot jet?

[GPracer2500]

We can't tell if your bike is rich or lean or what from what you've provided. What sizes are the main and pilot jets that are in it right now? What elevation are you at? Is your aibox lid on or off? Any other mods we should know about? How does the bike run other than starting?

When evaluating how the bike runs, pay attention to throttle postion--not what gear you're in or what RPM you're at.

0-1/8 throttle is the pilot circuit
1/8-3/4 throttle is the needle
3/4-WOT is the main

There is some overlap between those three circuits (and some other considerations) but that is mostly what you need to know.

[wohorsy96]

i dont know what altitude i am at. I'm in north alabama, but the problem only seems to be at idle, the bike screams everywhere else. I'm really thinking now that the plug may have just been fouled. What type of spark plug do they take? if anyone knows... i will pick one up on my way home tomorrow. i got it running earlier with the lid off. However i have not really had trouble cranking it until today. I cranked it yesterday just fine. But all i did was ride it down the street.

ya you might have too cold of a plug in their try if you ngk dpr9z plug that might be wuts making it start hard try using stock ngk dpr8z

[wohorsy96]

I'm not sure whats in there. i will try that tomorrow however. Thanks

[wohorsy96]

ttt

stay away from dynojet jets. and the pilot jets don't come in a kit. ii have a 42 in my wifes 400ex and it has less of the same problem as you described