If you've got the main needle out 2+ turns and there are no air leaks or contaminates, the idle needle is out o' wack.
When bringing it down slowly from full, does it seem to lean out? Does it 'blubber' when it quits?
Keep richening, (or leaning-depending on the circumstance), that Idle needle as you come down from full until you reach idle speed. Watch your exhaust for lack of smoke or unburnt fuel. Someone showed me that method at the field when I was new and getting fed-up with tinkering. I use it when I get a finicky engine. You just have to be very careful of that spinning prop!