1991 Merc 5.0 Stalls out on plane

Hi all. first post here! great site from what i can see. so here is my issue. I have a 1991 bayliner 2655 with a 5.0 merc and an alpha 1 with a 15x15 4 blade aluminum prop. Boat has a brand new aluminum tank, all new marine grade fuel lines, spin on fuel filter before the electronic fuel pump which are both also new, and then an inline fuel filter before going into a marine 650 holley 4bbl that was rebuilt because of the stalling problem. the carb does not have the fuel filter inside the inlet as i HATE THEM. I have been having this problem for almost a year now. BEFORE AND AFTER all new parts were installed(they were all installed due to a cracked fuel tank and everything was professionally installed by a boat manufacturing yard), is that when i get on the throttle and plane out, it will feel like it is out of fuel and go down to a idle and sputter and then come back. now here is the REAL kicker.... it will only do this on the ocean.. i can run wide open at the lake all day and not have a problem, put it in the ocean and boom, instant crap.. im a diesel mechanic and can fix about anything but i CANT figure this out and if i have to tell my wife i have to spend money on the boat to have someone fix it she is probably going to kill me. does anyone have any ideas? i have plenty of fuel flow, fuel pressure, new wires, plugs, all ignition wires are in great shape and no shorts

Are the ocean waves very high when it occurs?

No, it can be smooth out just leaving the launch ramp

do you have a mechanical fuel pump? If so, you probably have a pin hole inthe diaphragm. Stalling with fuel demand is typically of a failing fuel pump. Ethanol is a solvent and will deteriorate the rubber diaphragm. Does your craft idle fine, then after a minute or so when on plane it stalls?

Electronic marine fuel pump. Brand new. Had the problem before and after pump replacement. Runs for hours at idle and up to about 2000 rpm.

fuel lines new? Are you burning ethanol fuel?

Fuel lines are new and no ethanol

Ok check your vent first. You think it's not the waves. If you have a loop in your vent line maybe fuel is cutting off the passage. Maybe you have critters living in there.

Your fuel pump is giving 4-7 psi . I think a holly needs a little more you should know how many psi.

I would loose the inline filter if it's not a can style fuel water sep.

You catching air in from around a clamp ?

The fuel pickup tube is intact the anti-syphin valve is good?

Maybe junk and gunk gets stuck on the pickup tube the engine sputters down and the the junk falls off the screen.

You could run on the ocean with a portable tank of clean fresh fuel and see if it does it then , if not you got it pretty mush narrowed it down.

You could suck all the gunk and junk off your tank bottom.

http://baylinerownersclub.org/forum/newreply.php?do=newreply&noquote=1&p=581936

Seems I've heard of similar problems like stalling when the boat is put into a hard turn. In that case it turned out to be the float in the carb - don't recall if it had a leak in the float or was just hanging up when the boats attitude was changed. Going up/down the face of waves could affect the float in the same way as an abrupt turn.