Help! wont idle

[sprtrx300ex]

I just bought a new 400ex. WE brought it home and started riding it. We had it idleing and then it just shut off. WE got it started and continued iding. It kept on missing when u hit the throttle. I turn the idle speed up and it seemed to get better, but still doesn't have a real consistant idle. It keeps shutting off when u let it idle. What is wrong?
Also it is brand new. I noticed some smoke coming off the head pipes and a little coming out the exhaust. Is this just things getting broken in?
Thanks!

[ridered86]

it might be just in the break in process, what color is the smoke?

[sprtrx300ex]

the smoke was white and was coming from the head pipes and out the exhaust.

[tecate87]

sounds like running lean, might want to take back to dealer you got it from

[nazman01]

well, i had the same problem, but since yours is new it may not be the same, after going through everthing twice, i found out it was just bad gas, or actually some of the gas got gummy. I realized this was the problem when i drained the bowl, and then it ran fine for a few minutes. The is a screw on the left side of the carb by the bowl. just unscrew it a litte and the gas will come out the overflow, let it drain a bit then try runniing it again!! its worth a shjot, and dont cosdt anything!

[cals400ex]

mine smoked when it was new also. it only did it for a couple of minutes though. while breaking it in, do not let it idle too much. this will make it get too hot. make sure your idle is high enough and possibly change the gas.

[ridesa02400EX]

hmmmm mine does this to but it stops smoking after a few minutes i wouldnt worry aboout it