oneten's problem is it doesn't idle AT ALL (i am his friend) it runs fine till you let off the gas, i am guessing that it is not jetted for cold weather

pizza914- hey are you going this weekend?? we might be at florence (depending on weather) look for a black 400ex

kc

 

for easier starting, pump the thumb throttle lever a few times, theres an excellerator pump on the carburetor that shoots a small jet of gasoline into the intake, kinda like a primer on a lawnmower.

 

Since the idle circuit is on the slow/pilot jet that would be something to think about increasing in size, but I would try richening up the air/fuel screw first to see if that solves the problem.

 

Hey Dasandbomb, I kinda doubt I'm heading down this Weekend. If it was going to be dry & the roads were clear that would be fine. I could probably find a few guys to head up if the weather was ok! Give me a buzz if you guys are heading up. My name is Jamie Rust & I grew up in south Corvallis. If you guys ever get up Monmouth way I own Main St. Pizza here. Stop in for some chow & to say hello! Heck maybe we know each other from years back. I moved to Monmouth 8 years ago. Here is my cell 971-388-4674 or my store # 503-838-4040

 

try turning the fuel skrew out to 3 turns from lightly seated given you have the stock pilot jet in. also, raise your idle if it is too low. the idle adjustment is on the left side of the carb when sitting on the bike. it is a silver skrew you can adjust with a flat blade skrew driver or your hand.

 

Also, if you expect it to start when it's very cold, having some good fresh gas in the CARBURATOR makes it alot easier. There is such a small amount stored in the carb, it gets "thick" pretty fast, just a few weeks. I have found what's in the fuel tank is in much better shape than what got left in the carb last time you rode it. So if it's been sitting for awhile, turn your gas off, and drain the carb via the screw on the very bottem of the float bowl before you even try to start it. That thick old gas can foul your spark plug too, no matter how new it is.

 

u might be jeted to rich like mine change the plug and choke it i have to run rich couse i have nitrous

 

first of all its a 2002.LOL
mine is running fine in this weather

 

I took my choke right out and installed a 42 piloit jet. Last night it was approaching 0F and it poped and sputtered but after holding the throttle for a few seconds it ran and idled fine.

 

this is perfect advice

and also what 420EX said. (but it can also result in a flloded motor if you pump too much)

It defenitely sounds like you need more fuel on the idle. (and maybe more air)(idle adjustment)

It could also be a clogged pilot jet.

It wouldnt hurt to adjust the valves either (you might be pleasantly surprised).