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I have a Craftsman LT1000 model 917270712 with Briggs and Stratton model 311707 17HP Intek and nikki carb. I changed the round plastic part that the float attaches to, including the needle and the base gasket. The repair video said don't lose the part that goes inside the center bore of the round plastic assembly (see photo). I already threw away the old part and don't know if there was a piece in the center bore or not. Parts store said they can't tell if my model gets this part unless I bring the entire carburetor to them. Thought I would post photos here to
see if I can get an answer.

The main jet fits in that hole. Kind of important.