For those who don't know, the adjustable idle mixture screw is under this sealed plug, use a small drill bit and drill a hole, then pop it out with a pick or self tapping screw. I'm pointing to it with a pick.
Removing this will allow you to use carb clean and, hopefully, clean out the tiny passageways.
Removing this will allow you to use carb clean and, hopefully, clean out the tiny passageways.