After cleaning reassemble all parts except the pistons. Hook up a manual gasoline feed with about 2.5 feet of drop in the line. Give it 5 minutes or so to see if gasoline wells up out of the jet. It it doesn't your probably good to go. It it does then your float setting isn't correct or the needle and or seat are bad.
IMHO there is a very, very small change that the float has become saturated with gas and won't float properly. This is normally only a problem when the floats are hollow andget a leak. I don't beleive GW floats are. Weigh them on a diet scale or do a float test in a can of gas. All should weigh almost the same or exhibit similar bouyancy.
I don't know about the 1100, but the 1200 & 1500 floats are hollow and do develope leaks. At least 2 of mine did and that's what you should test first. Just shake them and listen for sloshing. As far as the needles go, look for something stuck in them that may be keeping them from closing properly.