Well, I tried to rotate the nipple and it broke off at the base. The plastic nipple is molded on a knurled brass stud that is probably press fit into the carb body. B&B has a metal replacement but I don't know how it is installed. I think the replacement is threaded but the carb body is very thin and I don't know if it can be tapped to allow the replacement to be screwed in. Plus, if I pull out the stud will this increase the size of the hole so that tapping will not be possible - e.g. the replacement will be too small?