Carbs need 3 psi. 7 psi will cause the float valves to leak and flood.

There are lots of used pumps in the yards but many of them leak the same
as the one he has. I finally fabricated a test stand to check them out
but they want to sell them to you first and let you test them later.
As I mentioned though, if the leakage is minor it is probably because the
pump has been dry too long and the rubber ring which was swollen has now
shrunk. They will swell again with gas on them and many times will seal well.
The alternative is to have them sit with gas in them for years which gums
up the motor so it won't turn.
--
George Downs Bartlesville, Heart of the USA!