Engine Sputter is back

[trayson]

Do you have a check valve inline on your vent hose? The length shouldn't really matter, so long as it's able to pull air through.

I really think running the boat on an external tank the next time you have the issue would go a long way toward diagnosing the problem, or at least pointing you in the right direction (supply-side or delivery-side).

I agree that probably opening your gas cap was the thing that made the difference that time, not the additive. I suppose you could also try just opening the cap next time it happens.

No check valve

So what are you thinking? Disconnect the fuel line that goes out of the fuel filter from the fuel pump and put that into a gas can?

Is there a loop or slack in your vent anywhere? Running it all the way to the front of the boat makes me think there is a low spot that could pool gas and not allow it to vent properly.

There is some slack in the vent line. It's a run that goes from the gas tank up to by the windshield so it's be hard to get a perfect slope on it...