What kind of electric inline fuel pump do you have?

[Surcouf]

Your float never perfectly fully seals, and so when you apply pressure on the carb, you overfill the bowl, and so you fill the carburetor body with gas, and if that happens, the very first place it will leak is from where you saw gas exit: the flame arretor and its connection.

this is exactly why your electrical fuel pump is only powered when you have oil pressure, starting when cranking. At least if your fuel pump is wired normally. Turning the key without cranking should NOT start the pump, as it WILL leak out of the carburetor bowl, one way or another.
Just think what was the situation with the mechanical pump: only fuel pressure when shaft spinning

No kidding here, this is a HUGE hazard...

[joe_db]

What is your fuel pressure?

[wetbirks]

What is your fuel pressure?

It got up to around 3 and then I shut it down when I saw the leak.

[ndutton]

There is supposed to be an O ring inside the air intake horn where it slips onto the carburetor:

https://moyermarine.com/product/flame-arrestor-o-ring-fcar_08-1_300/

It's normal for a little fuel to pool inside an updraft carb throat after engine shut down. The scavenge tube exists to extract that fuel into the intake manifold when the engine is running. However, it is not normal for fuel to leak out anywhere when the engine is running.

edit:
You think the inside of the carb looks clean? Looks like it's had a hard, wet life to me.

[wetbirks]

As a follow-up, I cleaned up the carburetor, reinstalled it and everything is running much better now. I also installed the fuel gauge and polish filter as recommended earlier in this thread.

[ronstory]

Nice. It's always good to get closure. ;^)

Did you end up with an OPSS?

[wetbirks]

Nice. It's always good to get closure. ;^)

Did you end up with an OPSS?

Yes I did!