High idle when cold

[-SuperMoto-]

Hi,

My 07 YZ250 has a really high idle for a few seconds when first starting the bike in the morning,it last's maybe 3 second's and then dies down to normal rpm,and then is ok for the rest of the day.

Any ideas what is causing this?

Regards,Ben

[yathump]

Do you have your bike setup to idle? Sometimes the normally raised rpms from starting with the choke on will be even higher if your bike is set to idle higher during normal operation

[rooster78910]

The choke will cause it to idle faster.

[harrperf]

Usually means your air screw/pilot setting is too lean...or for some reason its fuel starved at first start up, that's it the idle is REALLY high, almost like your revving it.

Otherwise...the choke usually makes it high idle.

[-SuperMoto-]

hey guy's.

OK the bike just about idles...I have to blip it every few seconds,I know the choke makes the bike idle a little higher but I'm talking like half throttle when I start it in a morning.

[adamscrf]

some bikes do this, it may be jetting a lil off too

[Fliip]

when my 02 yz250 was running, it did the same thing. I also notice some yz250's on youtube do that too.

[yathump]

You could also try leaning the bike over with the gas on until gas comes out of the overflow and then try and start it and see if that helps

[-SuperMoto-]

thanks I'll try that next time,as far as i'm aware jetting is stock,I checked the air screw and that is also stock ( 2 turns) as I'm in europe.

[-SuperMoto-]

You could also try leaning the bike over with the gas on until gas comes out of the overflow and then try and start it and see if that helps

That seem's to have fixed it,thanks!

[yathump]

That seem's to have fixed it,thanks!

Glad it worked out