I know that this is not a 4 cylinder Honda but it seems the Honda Twin site is unavailable. I have a 72 CB350 with Keihin 722A carburetors and it seems that there is a missing part under the top lid. I have two pictures.
The first is a picture of the part that is missing.
This is a picture of the underside of the top lid with the part installed on the other carb.
I believe that the bike was running without the thing, but not sure of its function. Anyone help?