idle problem

[keepitpinned]

i got a 400ex. its start no prob everytime but has a hard time idleing when it is cold. i have the choke on so it aint. once it warms up it idles fine. jus keeps dieing whenever the engine is cold. what can i do to solve this problem. also what should my fuel/air mixture screw be set at? I kno i will prob have to mess wit it a lil bit but wut place is best to start out with

[keepitpinned]

anybody help me out?

[buddy what not]

my 300ex used to do that but it was becouse my main jet was to small do u have a pipe on it?

[keepitpinned]

no pipe. the quad is bone stock. like i said it only does it when it is just started and cold. when it warms up it idles fine. Can anybody please help me

[muddy400EX]

thats what mine did to. you just gotta get it warmed up a lil bit.

[QuadJunkies]

Originally posted by muddy400EX
thats what mine did to. you just gotta get it warmed up a lil bit. exactly.:)

[keepitpinned]

ight guys. thanks. i just wanted to make sure my jetting wasnt off or anything. im freaky like that the little things jus bother the hell out of me. im gonna prob get a ziptie on it to hold the throttle open a lil bit so i dont have to sit their to keep it running

[KY Woods Rider]

I don't know what elevation you're at, but at my elevation (635ft) a stock 400EX is a bit lean on the pilot and pilot screw. It's not enough to be concerned about though, it just makes it a royal pain in the @$$ to get it started and keep it running. You could try backing out the pilot screw 1/2 turn and see if it helps.

Even when jetted correctly, the 400EX is a bit of a pain to keep running for the first few seconds. I just start mine and as soon as it fires up I turn the choke off and hold the throttle at a fast idle for about 15-30 seconds depending on how cold it is outside, then I give it a couple of really light blips of throttle, after that it will run fine.