Help -- please identify this part

[Kent]

[font "Arial"][size 2]I was getting the boat ready recently, when I discovered something that concerned me. I went to attach my fuel line to my 1963 Mercury 1000 outboard when I saw a loose part sticking out of the outboard where the fuel hose connects to it. I have attached a picture of it. Near the top are two rings and on the bottom are two flattened areas, at right angles to each other. Does anyone know what function this part performs? I started the outboard and ran it for a couple minutes with the part removed. If the part is necessary (which I assume it is or it wouldn't be there) does anyone know which end goes into the outboard (I was too stupid to notice this when I removed the part) and if I can just push it back into the hole where the fuel feeds into the outboard?[/size][/font]
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[font "Arial"][size 2]Thanks,[/size][/font]
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