Low power on take off

[nat85501]

1987 150 Black Max XR-2 I just got the boat when I did a test drive it ran 54 MPH with good take off. Now it takes me a few hundred yards or a few miles just depending on how it feels to get on plain. Then on occasion while on plain it will bog down for a few minutes then pick back up. There is no miss-firing it runs smooth. Also the guy I got it from took the oil-injection off so I have to mix my oil in the fuel I mix Quicksilver premium plus at 50:1 straight into the fuel. Also I can’t keep the fuel bulb full I pump it up several time and once it get full it goes soft again while running or sitting. I replaced the fuel line from the tan to the male connector into the engine bulb and all. I took it to the shop the guy changed the stator and voltage reg I have changed the plugs. I have lost take off power and about 5 miles on the top end I have no idea this is my first boat thanks for any help really it would mean a lot. The serial # is 08210338.

[boats.net]

Did they run a compression test?
May need carbs cleaned and synchronized.
Check the prop to see any damage to it from hitting something.