1988 Mercury Full throttle then bogs down

I have a 1988 25hp mercury. Starts like a champ. Usually 1 pull. Last year, i took it out and it would get me up on plane, then just bog down and idle. I would keep it at Full Throttle and let it run bogged down and it would take back off. It would get back up on plane for a few mins, then bogg down again. Cycle kept repeating itself over and over. I switched gas line and tank and gas and got the same results.
Any ideas on what i should try to remedy this?

Fuel pump weak? Did you try pumping the bulb when this happened?

Jeff

Tried pumping bulb and it stayed hard. I was wondering if it was the fuel pump.

Squeezing the bulb replaced the action of the fuel pump....you can run your engine without the pump if you keep the bulb firm....for a data point-not a common practice....but with the engine running the bulb should remain soft, not hard....hard is what you want prior to starting the engine. Says to me you have a clog in the fuel delivery system, like maybe a dirty fuel filter, or your fuel lines are breaking up on the inside (rubber deteriorating due to age) and the little rubber particles are floating around around and clogging the filter or the carb.