Help with carb rebuild, where does this go?

[country 0]

I'm rebuilding the carb on an 11hp Briggs, and don't know where this little round rubber grommet type is supposed to go. I can't find this part in the old parts that I removed. Is it supposed to go somewhere?

Above is the carb, with the little part towards the bottom right.

Above are the parts removed, with the little rubber piece shown in the only place it seems to me it will fit.

Another pic of where it seems it would go. Does it go here? If so, does it get pushed all the way to the bottom of the tube? Is it used at all? Thanks!

[BLT 715]

If one of the sides has a groove on it, that is the seat for the needle valve. You should have one of those in the needle valve hole or a brass adaptor, depending which needle valve you are using. It should be on instruction sheet that comes with Briggs carb rebuild kit.

[country 0]

Thanks Bob (BLT). The only instructions that came with the kit were for setting for float. One side of the grommet does have a groove, and the bottom of the bore for the needle valve is just flat bottomed in the aluminum. Does it matter if the groove in the grommet goes in face up or down? Thanks!