1984 75 HP Mercury outboard motor Problem?

Question

I have a 1984 75 HP Mercury outboard motor, it runs good when it’s out of the water, BUT when there is a load behind it, in the water is bogs down and dies. I’ve had the carbs rebuilt, fuel lines replaced, fuel tanks cleaned, filters added, stator replaced and the certified mercury mechanic spent 5 hours trouble shooting Saturday and can’t find the problem. Does anyone have any suggestions?

Answer 1

i just had this problem 84 75 4cyl checked everything also.put muffs on take carb cover off and start.look at carbs see if fuel is going in carbs or running back out.if fuel is running back out need to check red valves only way to do that pull powerhead pull front cover and look.had pull my down didn't see anything pulled crank up just a littlte bit to unbolt reed blocks found loose screws on bottom reed block