What is this carburetor part called and where can i get it?

[kappy]

Hi y'all,

I've got seemingly endless issues with my 1980 CB650 which has been at a mechanic basically the entire season

After he picked apart and cleaned the carburetors, they have had issues with leaks from the drain pipes on the bottom of the carbs.

The mechanic believes that it comes down to this part (see attached image from a Youtube video, he's referring to the part which the finger is pointing at.)

The issue is now that I (nor him.. ) can't really find a replacement part. I'm not really sure what it's called nor what to search for online. Anyone that could point me in the right direction?

[Volker_P]

This is the floater needle seat. It might become leaky when clogged or damaged.
I recently wrote a bit about this issue here.
Not sure where to get these parts for the CB650 piston carbs however.