I have a 95 4.3l mercruiser that idles and runs fine under 2k rpm. It will accelerate fine at full throttle but, after about 10-15 seconds it starts bogging down as if its running out of gas. The rpm will gradually decline and it will start to pulsate until it slows down to around 1500-2500 rpm and eventually it will start to pick up rpms and then the entire process starts over again. Originally i thought it was the fuel filter. That has now been changed with no noticeable improvement. Next i cleaned the carburetor. Pulled the metering rods out and cleaned the carb with carb cleaner. Still no noticeable change. I noticed today that when it starts to bog down the fuel gauge pegs to below "E" as if the ingition was turned off. I'm thinking that the fuel pump is going bad? Possibly shorting or binding causing it to pull more power? I hate to go buy a fuel pump for $200 to find out it is something simple. the boat ran great a month ago. I put it back in the garage and the next time out i was running about 4k rpm, it backfired and then has not ran the same since.
