Plugs on PHBH30 carburetor body

[Pescatore]

I've cleaned this plug on the carb body 3 times now, to convince myself that it is leaking.
It's more of a wheep, after long rides.  Both carbs are doing it.
What is it for?  Can it be replaced?
Internet wisdom says it's an expansion plug that you set with a punch.

[guzzisteve]

That is the breather for the bowl, may be a small hole that pukes fuel. Have a close look hole will face down. Some had a tube there or strait across on back side.
Look in the well, up at bottom of that pressed in cap, should be a hole in it.

[Pescatore]

Thanks guzzisteve, I just found this, #10



So gas is evaporating out of the hole?
I guess there's no stopping it.

[guzzisteve]

If the float is set correctly, maybe some dribbles.