Beta evo 250 recently cleaned carb & runs fine only issue is I noticed the air screw is all the way in. Will this be fine. I screwed it out 1.5 turns & it made it run a little worse. 

That indicates that it probably has one of these things happening:

Pilot jet or pilot jet passage restricted.

Too small a pilot jet.

Air leaking into the motor somewhere other than through the carby venturi.

If it didn't have the problem before you cleaned the carby then it's not option 2.

I'd first check the mixture screw spring, washer and rubber are all there and in the right order.

Pilot jets are all clean & blown out. Funny thing is it runs just the same. When you rev it revs come back down nice & steady. Nothing really changes when you screw it out when it's ticking over revs don't increase. I ran it on sat all the way in & 1.5 out & didn't really notice any thing different between the settings. Temp was around 5 degress C.

Pilot cleaned & also the small passage in the body cleaned out.