Does seafoam work in the fuel system. Engine was bogging and had poor acceleration after several hours in the water.

[1985 Century Mustang]

Today after a 5 hours on the water, I started losing acceleration as it bogged down, some times almost stalling out. The engine took a few seconds to shut down when I turned the key off, it was sputtering for a second or two and then it shut off. Never did this before.

When I got back, I removed all the plugs and they were perfect. This carburetor was fully rebuilt just several months ago, and I didn't have any issues since today. However when I rebuilt the carburetor I couldn't remove the plunger when I did the rebuild, so I cleaned it as best as I could. Maybe that could be the issue, who knows.

Before I remove the carburetor I'd like to know if a fuel additive might help. The water separator filter is pretty new, and I checked all the fuel filters, which looked fine.

What should I check next, and would the seafoam fuel additive do any justice? I get gas on dry land from a reputable gas station that sells and moves a lot of gas, never had issues w bad gas at that station. Your thoughts.

 

[1985 Century Mustang]

PS - I also noticed there was a ratty smell of gummy gas when this all was happening. It literally smelled like water was in the system, or bad gummed out gas was in the fuel system.

 

[1985 Century Mustang]

I suppose I could check the water separator also, which I haven't yet.

 

[1985 Century Mustang]

If so which fuel additive would you recommend?

 

[Scott06]

Check the contents of fuel filters and moisture separators For anything but clean gas .

Run it on a separate outboard tank with fresh fuel. If problem goes away Suck all the gas out and clean the fuel system, verify tank vent is clear and hoses are not internally degraded.

as long as power valve plunger moves freely it is fine

 

[1985 Century Mustang]

Check the contents of fuel filters and moisture separators For anything but clean gas .

Run it on a separate outboard tank with fresh fuel. If problem goes away Suck all the gas out and clean the fuel system, verify tank vent is clear and hoses are not internally degraded.

as long as power valve plunger moves freely it is fine

I'm gonna pump some fuel into a glass container and check it also, as advised by an auto mechanic friend of mine.. I have an electric fuel pump on my engine so it won't be to hard to do.
How would one verify the tank vent is clear. Please be specific, location etc... Thanks

 

[1985 Century Mustang]

I'll try opening my gas cap too see if that does anything.