When you take the idle air screw out you're leaning the mixture; if the idle won't drop as you turn the screw counter-clockwise then you are running too rich on the low side.
You may want to try dropping the needle down another notch (raise the clip), a #125 jet should be good if you are at a low elevation.

 

By screwing the fuel screw out(counter clockwise), aren't you richening the mixture??

I checked the plug and it looks perfect, I don't think it's running rich at all.

The idle still will not go down if I turn the screw out. [&:]

 

The idle fuel screw does adjust the amount of fuel in the idle circuit so when you unscrew it it allows more fuel in thus richening out the mixture, (my bad) I always revert back to my 2-stroke days for some odd reason.

When I say running rich (or maybe lean in your case) the idle fuel screw only controls the mixture from idle up to about 1/8 throttle so the bike may be dialed in just above idle; what you are trying to do is get the idle mixture correct now.

You may want to turn the fuel screw 1/8 to 1/4 turn at a time and then ride the bike for a short period to see how it responds to each adjustment.

The needle can also have an effect on idle depending on how deeply it is seated into the main jet and where your idle stop screw is positioned so by moving the e-clip further from the pointy end of the needle you are leaning out the mixture at low throttle settings.

Your bike may be running better then it did stock (that isn't tough to do) but it is not quite dialed in yet.

 

Clockwise or counterclockwise?

 

How is your bike running?

 

Starts right up and runs real strong. No hesitation, good power, no popping on deceleration. It just won't wheelie! [:@]

 

I wouldn't mess with it then.

Oh and it will pull a wheelie, you just have to get the R's up and dump the clutch then throttle, feather, throttle, feather, throttle, feather.

 

This is the only thing I'm really disappointed with the KLX. I never had a bike that wouldn't wheelie by just whacking the throttle in first gear. Even my bone stock XT225 would stand up with the snap of the throttle.

So I guess I now have to learn good wheelietechnique instead of just relying on engine power.

What's a good RPM to dump the clutch?

 

Anything less then 5K and it bogs down and the front tire falls off before you reach the balance point (which is high on this bike), I hit it at about 7k.

Practice on the grass (sit back, don't ride the tank) with a large crowd of people for moral support, a wife or gf nearby with a video camera is always a plus, and don't forget a couple of beers and handful of Ibuprofen for later.

Remember; the secret is in the clutch to get her up and the rear brake if you're going over.