Run the idle screws in all the way gently and count the turns it takes to bottom them out.
Pull them out and shoot some WD or whatever in the open holes, and then hit both with compressed air.
Put the screws back in and again gently bottom them, and then back them out to the same amount of turns.
Sounds like the carb idle circuits are plugged up with crap from sitting, and most of the time this works to clear it.
The fluid type you use to spray in the holes doesn't matter that much, as it is only to give the air a bit of weight to carry the junk out.
