engine warming up issue!

[Jimford]

Hey whats up? I don't know if anyone else has this problem with their 400ex. I'm sick of starting everyone elses quad. One light push of the start button and pow it's started! they idle perfect and the rpms raise when they warm up when the choke is on. My 400ex starts up after a couple cranks of the starter and even when the choke is on I have to play with the idle screw the make it idle by itself. It stalls 20 times. I just adjusted my valves not to long ago. It runs perfect when its warmed up! What the hell is wrong. I feel like an idiot restarting my quad 10 times when everyone else's is warming up! Any help is appreciated. Oh and I didn't look this topic up in a search either so please give me some advise! Thanks!

[dirtmomma]

Our 400 is the same way, I will admit the valves need to be adjusted but it's always been a cold starter!! It takes a good 5 min to get er warmed up it spits & sputters LOL don't know what to tell ya but let it warm up!!

[JOEX]

Put a 40 or 42 pilot jet in and it will be all good;) If you don't know how do a search or check the FAQ section of the forum and get a repair manual:)

Joe

[RED121572]

I bought my 400EX in the dead of winter four years ago. Mine did the samething. My buddies had to stop me from using the quad for a rifle target.

It didnt get better until I up'ed the pilot jet size.

[Jimford]

Thanks I will try a diff. pilot jet. But I will wait until I get my e-series tomarrow. Do you think I should go even bigger with my new pipe or will it be all good. I've been working on these things for over 10 years. But jetting has never been easy for me. Thanks :D

[ReconRider25]

pilot should be good with the 40 or 42 but ur gonna have to go up on th main and maybe change the position of the clip on the needle

[RED121572]

When you get your slip on, go ahead and up the pilot one size from stock. She'll start real easy.

My pilot is still one up from stock. It starts within the second turnover, even if its 10 degrees out..without the choke. I think I may have gotten lucky when I tuned it.

Good luck. Let us know how that pipe treats ya!