Looking for ideas before I discard a half tank of fuel

[lilboatsman]

My 1989 Arriva purchase this year had a cracked 5.7 Mercruiser block, so I never tried starting it. I purchased a 1986 Celebrity junk boat, 5.7 fired up and ran well before I pulled it. Swapped the motors, and now I can't get the motor to work in the Arriva.

When I dribble a little fuel into the carb, it fires right up for a few seconds. When I pull the fuel line from the mechanical pump, it has a fuel that dribbles out, so the pump seems to be working. The fuel shutoff valve is open.

Any ideas? The tank seems to be about half full. Maybe the fuel is bad, but could it be something else?

 

[Bondo]

Ayuh,.... Use a remote tank of fresh clean gas hooked to the fuel pump/ fuel filter,....

Ya might have to pump out the liquid in the tank, I hesitate to call it gas,...
Cleanin' the tank can be problematic, dependin' on how bad it is,....

 

[lilboatsman]

Can I just stick a hose into a can of gas? Or do I need to use something like an outboard tank?

 

[gm280]

"Dribbling" fuel coming out of the fuel pump doesn't sound like the fuel pump is working to me. There should be a good flow coming out of the pump. But without seeing what you say is a dribble, that is only my opinion. Does the fuel in the tank actual smell like gas, or some other harsh smell? If it smells like gas, it probably is still good. But again not being there and smelling for myself, it is just my opinion. If you are using the same gas in carb for it to run, then the gas is still good but it points to the fuel not making to the carb. And that could be a fuel line plugged up, a fuel pump bad, or even the carb needle and seat stuck closed or even some thing as simple as a fuel tank vent line plugged up. So verify everything to see what is the culprit. JMHO!

 

[Bondo]

Can I just stick a hose into a can of gas? Or do I need to use something like an outboard tank?

Ayuh,.... Whatever ya want, just don't spill it into the bilge,....

 

[fhhuber]

Ensure plenty of ventilation if using a hose stuck in a fuel can to test run the engine.
And bungee the fuel can so it is hard to accidentally knock over.

 

[redmen62]

I'm thinking the same thing as GM, it should be way more than dribbling out of the pump... but if that's the pump that ran the engine in the Celebrity, AND you're certain you didn't knock anything out of adjustment when installing it, then it sounds like something in the Arriva

I'd start with using an external tank straight to the carb fuel intake and see what that does for you. If she fires off and runs then it's a fuel delivery problem. If it runs, take that same tank and attach it on the tank side of the fuel pump, if it starts and runs using using the fuel pump to get gas up to the carb, it's not the pump.

I went through this 2yrs ago when I did an engine swap on my 68... ended up accidentally crimping a fuel line along the way and didn't know. Out with the old copper lines, in with braided lines and we were off and running and haven't looked back!

 

[lilboatsman]

I setup a remote tank connected to the stock fuel pump, and it starts with ease. But at the same time, I have been able to get it to fire right up after pouring fuel into the carb that came out of the boat tank. I pulled the vent line from the tank so I know that's not an issue. The only thing I can think of right now is the hose from the tank might have a small crack that doesn't leak fuel out, but allows air in?

 

[lilboatsman]

A $5 hose from the tank to the water/fuel separator connection, and I'm in business. I've heard of hoses having small enough cracks that air can get in, but liquid won't leak out. Never experienced it until now.

Thanks for the help diagnosing it everyone. Now it's time to align the motor for the drive. My alignment tool should be coming sometime today.