Outboard engine issue, Starving for fuel

Hi

At first I couldn't get my Merc 50hp 4 stroke efi to start. I flooded it with some seafoam and let it sit. Now it starts up like a champ but once I get past about 3/4 speed the engine starts to starve. I've replace the line from the tank to the engine but still starving. I haven't replaced the tank yet. Could something be blocked in there? Needs a new filter in the engine maybe? Any simple suggestions you have will help. Thinking it isn't a serious issue just something is blocked somewhere and would like to try some simple fixes before I trailer it up and send to the mechanic along with my checkbook

Thanks!

Nuzp

Has the filter ever been changed?

May or may not help you, but;

I had this problem with my 25 omc 2-stroke carbureted. Removed carb, cleaned, happened again and again. Cleaned carb, happened again....
Struggled for a few years with it running well, then not, then well, etc....until I installed a fuel filter after the fuel pump, and another just before the carb...my motor has run perfectly for years now.

Looks like I found the problem or at least one problem. The fuel pump is leaking gas like crazy.

Try bleeding the Vapour separator tank. Might have to remove a bit of the chap for easy access but drain the fuel out and check for water and debris. Put a new fuel filter and try it out. I had a bad gasket on the fuel tank and caused a number of issues with debris In The fuel tank

If the fuel pump is leaking like crazy that’s your issue.

I had the same thing happen with my 115 opti and the fuel float has a sensor for the water at the bottom end of the float. The sensor runs through a plastic screw in housing. That plastic screw is full of apoxy. The apoxy rotted out causing the leak.

I did not see this post until today or I would have chimed in sooner. First of all, if gas is leaking out, that means air is probably leaking in.

There is a very helpful site on line that is full of motor gurus for any kind of motor. You go into the site that pertains to what brand motor you have. These guys are mostly professional mechanics and their info is totally free. On your search bar, type this: iboats.com forum Then go into the category that fits your motor or your boat or your trailer, etc. They help me out a lot on all of my questions. Try it all if you have a problem. They even have a section for I/O's.

They will diagnose your problems based on the symptoms, and tell you what you need to do to fix it. They are great!

UPDATE. Replaced the fuel pump and no leaks there but have another leak. There is a small drain hole at the front bottom of the engine and when I pump the bulb gas leaks out of it. Back to the drawing board. I will check out that site Iggwy1 suggested. Tried uploading a vid but pictures only I think.

Ya, I think my float or needle is stuck in the VST causing it to dump fuel out the overflow hose. I'll have to do some research as I have never removed or cleaned a VST and don't want to make the matters worse as that is an expensive part

Maybe check the fitting at the tank. It could be loose and sucking in air. Also check to ensure fittings on the hose haven't come loose.

It was the float & needle in the VS tank. Been waiting 3 weeks for the replacement kit.