The crud in the top, is generally the result of having the crankcase vent hooked up to the back of the air box. The oil vapor etc collects in that area. Clean it up and relocate the vent line below the bike with a small filter on the end, or do the Erbman crank vent mod.
Try a combination of carb
cleaner in a spray can and a piece of fine wire or a nylon broom bristle that'd fit in the hole and keep working until it works.
Make sure the small oring is still in place on the bowl flange. It sits in the small round depression with the little hole in the middle. That's part of the fuel passage system for the accel pump.