[EE]

hello, i'm new here. we have an 04 model w/1000 miles and have recently experienced problems with achieving proper idle speed. it occured all of the sudden. thus far i have :
cleaned the fuel tank, new premium gas ,installed an inline filter
inspected all vacuum lines and boots.
the carb has been off and completely cleaned, with solvent and compressed air.
the air screw has been unplugged , cleaned and adjusted
new spark plug installed
air cleaner inspected

the machine will run fine at speed. no problems here or starting up. but after warming up after a good two mile ride it fails to idle. if you set the idle up with the plastic thumb screw the engine will raise in rpm's but when you blip the throttle the engine will race at a very high rpm until you unscrew the idle adjuster back down. upon doing this the engine speed will decrease until it will idle down slowly and stall. at this point it's impossible to find the proper idle speed.
one more note, after unplugging the factroy sealed air screw and making adjustments to it...it has NO effect on idle speed at all even when completely removed......? this screw should cause the rpms to change or run rough , correct??? i thoroughly cleaned this passage way ,which leads to the carb throat area as well....

this seems to be a common issue with these bikes.. i would appeciate any advice before we take it in. i must confess i am a two stroker at heart, this is really my first try with a 4 stroker. i'm suspecting that maybe one of the diapraghms on the carb could be the culprit??

thank you !