rich or lean?
 

The idle speed raises when the engine gets hotter, is this an indication of being to lean or rich? The bike generally runs good. Sometimes it stutters then clears at full throttle when under load, like up a steep climb.
Heres's what Im running.
2007 klx 250s
bill blue mikuni pumper carb
needle 3rd slot down from top
pilot 142.5 airscrew about 2.5 turns
main 142
no lid on airbag
wmf q4 slip on stock header
foam air filter
mcm done

Thanks for any help

What elevation?

In a very broad generalization, when a carbed engine tends to idle up as it warms up, it points to a lean idle/pilot circuit condition. There are exceptions of course.

I have a TM36-68 carb on mine. I recall Bill uses the 34mm version of this. I'm not recognizing the part you describe as 142.5 "pilot". Regardless, it's pretty tough to diagnose another's carb issue on the internet, but more detailed info usually results in better results. Part of the problem might be the airbag on your KLX blocking you airbox intake opening.:D

I have a BB33 @ 3300' and my pilot jet is 25% of the main. I assume you miss typed the 42.5 as 142.5.
I would either try a larger main or smaller pilot jet.

Umm yep I'll remove the airbag from the airbox��
Probably should be a 42.5 pilot jet. But if the air crew is out about 2.5 turns isn't that an indication that the pilot jet is correct?
Altitude is from 1000' to 4000'.

I am running my screw about 3/4-1 out, depending on altitude.

LOL!...no, I was just joshing about your statement, "no lid on airbag"...all in fun. On your air/fuel screw adjustment, it can't completely compensate for a slightly out-of-ideal pilot jet for the idle circuit, so I wouldn't judge the results of your air/fuel screw adjustment.