Bike running very lean.. any suggestions?

[wday12264]

I have a gz250 2003 that up until a year ago was in storage for 2 years. I got the bike started but it had some idle issues. I pulled the carb and soaked parts to remove varnish, buildup etc., and reinstalled. Still could not idle without full choke and even that was rough. Pulled apart again with another friend with more breakdown experience. Still not any better. I can only get a smooth idle if I cover the air intake 3/4 with my hand, and then I can work the choke down to a normal level. Any suggestions of a fix short of shop time?