Using TC's info: anything over 4.5psi is absolutely a NO NO. Agree with reset float, AND the drop, to specs. As has been said by several, carbs leak there for several reasons: Over flow from bowl, too much pressure, float leaking/sinking. Hope your "new" fuel pump is not an electric you forgot to tell us about. The correct stock mechanical pump would not need a regulator. I actually have never heard of a regulator on a carb engine with mechanical fuel pump.
