PZ30 carb issues

So I've got a df250rtc with the pz30 carb on it. For the last week or two, it's only been able to run on half choke, which means she's running too lean. So I took it apart, cleaned the whole thing out, especially the jets, and put a new filter on it. Now im stuck in the tuning stage.. I take off all choke, crank the idle way up so it doesn't stall, and start fiddling with the air screw. I'm still not getting any differencet in power/response. I've gone from all the way turned in, to all the way open. On its current setting, I'm getting smoke out of the exhaust, and bogging at over 5k revs. Also when in neutral and I'm just pulling on the throttle, it will stay up in revs and slowly fall back down to ~2.5k (what I set it at to not stall). I'm stuck, and no matter how I adjust it nothing changes much, sometimes ill get backfire in the carb and smoke will come out of the filter, but not on the current settings. So, am I still to lean, or to rich. I'm also confused as to which way turning the air screw will richen/lean the mixture. I've just been tampering to try to find the highest idle.

http://www.walbro.com/media/22805/pz-tune.pdf

Thanks! I'm assuming my jets are too small because she still won't idle and respond right with no choke on. I went ahead and ordered the Mikuni pz30, I hear they are better quality and jets are obtained easier.