Optimax Pro XS loosing RPM's and power while crusing

[jsmcobra201]

Serial # 2B110471

Ive got a Opti 250 Pro XS with a strange issue again. In about May/ June of this year I had issues with my motor just sort of loosing power at about 4,000 RPM's. The engine would run strong, get me out of the hole, and after a minute or two it would just start loosing RPM's and power. I went here to BBC and the general idea was that my grey fuel lines had gone bad. Went to AutoZone, bought some regular fuel lines, replaced them, and that seemed to cure the problem. Until yesterday.

Yesterday morning I sort of felt some minor surging and loss of power at times, but then in the afternoon it became worse. Now I cannot get it to go over about 4200 RPM. It feels like it wants to run, but again it sort of feels like its running out of fuel. I can push the hot foot all the way down and it wants to run, but it gets to 4200 and then falls off, then surges back up to 4000 rpms or so, and then falls off.

I took a look at my new fuel lines and this time I noticed that they sold me fuel lines for carbureted engines (SAE 30R14T1) lines. The old fuel line looks like it was SAE J30R9 - which I believe are rated for higher pressure. Could the problem be these fuel lines? Could these fuel lines be sort of pinching in at the higher RPM's as it's trying to suck in more fuel?

My primer bulb wasn't collapsed, and it felt firm, but could that be part of the problem too?

I have Mercury Vessel View on my phone, I checked and there are no faults reported.

Any ideas??

[EuropeanAM]

I'm going to suggest you start from SCRATCH on the fuel supply system. NEVER buy automotive fuel lines for your Marine engine, as it is not rated for (or approved for) that use.

The following post describes what you will need to do. Follow it precisely, methodically, and don't skip (or substitute) ANY of the components:

FUEL LINES AND PERFORMANCE PROBLEMS

[jsmcobra201]

I'm going to suggest you start from SCRATCH on the fuel supply system. NEVER buy automotive fuel lines for your Marine engine, as it is not rated for (or approved for) that use.

The following post describes what you will need to do. Follow it precisely, methodically, and don't skip (or substitute) ANY of the components:

FUEL LINES AND PERFORMANCE PROBLEMS

Thanks for the help. It sounds like the best thing to do is replace the automotive fuel lines with Mercury/ Quicksilver lines. Replace primer bulb - also with Mercury/ Quicksilver parts, replace fuel filter and re build pulse pump if I see signs of deteriorated fuel line in the separator?

[EuropeanAM]

I would do all of those items, period. Regardless of what items may "look" like. This way you will know that things are as they should be, the fuel supply is good, and you can then determine if any other problems might exist.