Fuel issues

[Gacreekz]

I have a 78 ski supreme with a 351 Cleveland in it and a Holley 4 barrel carb. I’ve been having issues with fuel the boat will run fine for a couple of minutes then start sputtering the next. I got to looking and there a vent hose coming off the fuel pump that is just run and sits on the engine. The air filter on top of the carb has a barb that comes off of it and I was wondering if that vent line off the fuel pump should be hooked up to that barb on the filter.

 

[Sprig]

That is not a vent hose. It is a bypass hose for the fuel pump in case the diaphragm goes bad so that fuel will not leak into to bilge. Yes it probably should plug into the carb. That is not the reason for the sputtering. The problem could be due to a number of things. Sputtering is usually due to fuel and not electrical.The first thing I’d check is the fuel filter. Check it and if there is debris in it or it hasn’t been replaced for a while then replace it. It could be the carb itself. May need cleaning or rebuild. It could be the fuel itself in that it has water or other contaminates in it.
Do you ever use gas with ethanol in it? If so could be the inside of the rubber fuel lines have deteriorated (if they aren’t the newer fuel lines). When this happens you get little pieces of rubber in your lines that usually clog the fuel filter.
Im guessing the problem is clogged fuel line or fuel filter or carb itself.
When is the last time it was tuned? May need a thorough tune up.

 

[73 Dolphin]

I had a 70s starcraft chieftain with a mercruiser 165. Sometimes it would run all day other times it would die just off the dock
and I had to be towed back in. I went through all of the usual things. Filter, carbs, float,etc,etc.
Turned out to be the no return valve ( anti siphon ) on the fuel line had a tiny piece of debris in it. Changed it out for a few dollars and never had an issue again. Probably not your issue here but worth a look at.