I see this on occasion. There are several good fixes. First inspect the gasket surface to see if it is damaged or the old seal is still in place. Yes, I've had quite a few carbs come in here where the seal was still there but difficult to really tell as all the black coating was missing from it.
Once you are sure they aren't doubled up insure no material is left on the gasket surface.
If it's pitted out lightly or just has a minor imperfection and scratch on it, you may be able to put some grease on the bottom of a used fuel inlet seat and tighten/loosen it to gently form a new seat.
That's the best fix.
You can also obtain a thicker fiber washer, but that throws the geometry off some, so you'll have to bend the float arms to compensate.
For seats that are really pitted out the best fix is to coat the threads of the new inlet seat with Marine Tex. Just use enough so it fills in the pitted areas and seals things off at the threads. Still use the gasket under the seat to keep geometry correct.
If you even have to go back in and rebuild the carb again, which could be many years, you can gently heat the seat with a propane torch to release the epoxy.
Of course using epoxy isn't my first choice for that type of repair, but it is 100 percent effective, just make sure you don't use JB Weld or some other type of "monkey chit" that doesn't hold back fuel!......Cliff
