Mariner 4hp 2 stroke 1986 runs too rich

[forsailbyowner]

I bought the motor used and its never run quite right. It sounds ragged and rough until it starts to run out of fuel then takes off like a banshee for a second then dies. I put a kit in the carb when it wouldnt start and I found a hole in the pump diaphram. After putting the kit in I didnt torque the carb down tight enough and had an air leak around the gasket and it ran super, until i tightened it and again with the poor performance. Im wondering where is the problem that is causing the rich condition? Somebody prior tried to drill out jet for more hp? Wrong carb for engine? Incorrect float height? (having no specs I set it so float is level when inverted) Really not wanting to just start throwing money at parts with no real clue. Thanks for any help.