Motor bogs once on plane

[tmass32]

Hi all. Long time reader, first time poster. Very helpful.

I have a 93 OMC 5.0 with Holley 2brl that had been run sparingly over the last 2 seasons. Was running very erratically the first few times out this season (rough idle, stalling under throttle, gasping) but has been running much more consistently as of late but I have noticed something odd.

Motor runs well throttling up (boat tilted back during acceleration) until I get on plane (flattens out). Once on plane it runs okay for a time then begins slowly bogging down to ~2500 rpm and out of plane. Then consistently runs well accelerating at an angle until flattening out.

New fuel/filter, oil/filter, plugs before season started. I suspect something in the tank/pickup but any suggestions are welcome. Have a carb rebuild kit handy but hoping to avoid that as my water/problem solving time is limited. Thanks in advance everyone.

 

[kenny nunez]

Get a 6 gallon outboard tank and connect it in place of the tank fuel line. Take it for a cruise and see what happens.
Pull the fuel suction line out of the tank and check if there is a small filter inside of the suction line.

 

[94 Sundowner]

I have a 94 omc cobra 5.0 fuel injected that is doing the same thing after I put some fuel stabilizer in it . At plane it will slow down on it's own and make a popping noise from the engine area and sputter . I will put back in neutral and it will go again with no problem full throttle and 5 minutes into it will repeat itself . I have since changed out the plugs and water/fuel separator filter with no luck . I have a video of it but this site wont allow me to upload it . I also have an appt with the mechanic this month in Oct .