Boat Straving for gas

[anthony10092]

I have a V8 350 magnum motor with an edelbrock carb. When I start the boat up it idles perfectly, and free revs just fine. When I get it into the water and put it into gear it will run fine for a short period of time then it will stall out. But it will always start right back up. I have cleaned the carb and checked everything. I just put a new mechanical fuel pump on. When the engine dies I have taken the carb apart on the water and see that there is no fuel in the bowls (or very little). The needles are acting the way they should be so the problem is not there. If I disconnect the line into the carb and turn the engine over it will pump gas into a can. So the pump is pumping fuel. I am at a loss on this problem, any help would be great.

Thanks

 

[Bravo]

Re: Boat Straving for gas

I had an old quadraturd Carb on a truck that did that exact same thing. Turned out to be a faulty fuel filter. The quad Carb has a internal filter that was getting twisted when tightened in place resulting in a restriction. I'm not sure what type of filters you have, but check it. Possibly in the water/fuel separator, or maybe a kinked fuel line. Whatever it is, it should be simple, so start with the easy stuff first. Good luck!

 

[anthony10092]

Re: Boat Straving for gas

I just pulled the inlet off the carb and it was bone dry. The pump doesnt seem to be pumping the fuel up. Its brand new though. Where is the anti-siphon valve located? I am wondering if there something wrong there.

 

[Aviator5]

Re: Boat Straving for gas

Once I had a piece of dirt stuck in the anti siphon valve, it did exactly what you described.

 

[bds85466]

Re: Boat Straving for gas

So obviously sometimes it's getting fuel. If the fuel pump is new, I'm doubting it's that. I'd guess something else in the fuel delivery system. Filter, gas tank not venting, in tank strainer clogging? -- if something is suction clogging, it would be fine right after you turned it off, and then it would build up again, and again, until it was actually cleaned.

I've also heard oil switch and oil sender(?).

http://forums.iboats.com/showthread.php?t=399859

 

[Fishermark]

Re: Boat Straving for gas

Try hooking up a portable tank and see if it pulls from that. It will help with your diagnosis - eliminating or pointing the finger at the tank or line, etc.

 

[Rocky_Road]

Re: Boat Straving for gas

I just pulled the inlet off the carb and it was bone dry. The pump doesnt seem to be pumping the fuel up. Its brand new though. Where is the anti-siphon valve located? I am wondering if there something wrong there.

Your anti-siphon valve wouldn't cause this...but if your gas tank vent is not clear, you can create a vacuum in a short time and choke off your fuel flow to the pump. In this situation, waiting awhile will release the vacuum and you will start again.

The easy way to eliminate a clogged vent as to being the problem is to simply 'crack' the gas cap allowing air to enter if necessary. If the engine keeps on running, you need to clean out your tank vent hose and vent. Mud wasps in my neck of the woods love to nest in the vent....

Happy boating!

 

[anthony10092]

Re: Boat Straving for gas

I am on my way to find a different fuel tank. I have cracked the gas cap and did not hear a vacuum noise. It will run in gear at 1,000 rmps all day but dies after you give it more. I will post what happens after I hook it to an external tank. Thanks for all the help so far...

 

[dirtyoldman]

Re: Boat Straving for gas

I am on my way to find a different fuel tank. I have cracked the gas cap and did not hear a vacuum noise. It will run in gear at 1,000 rmps all day but dies after you give it more. I will post what happens after I hook it to an external tank. Thanks for all the help so far...

You are aware that there is a filter on the carb inlet line, right?

That one has gotten me a few times now.

 

[anthony10092]

Re: Boat Straving for gas

Problem solved. There is no filter on my carb, there are just the two screens that are in the seats. The fuel lines were so bad that they were collapsing and breaking down and filling the screens in the carb. I replaced the fuel lines, cleaned the carb, and cleaned the anti-siphon valve. Thanks everyone for the help and input.

 

[Bravo]

Re: Boat Straving for gas

That's great! I do, however, advise you to get a fuel/water separator. They're cheap and can be bought at marine supply places and I even think wal-mart has some.

 

[dirtyoldman]

Re: Boat Straving for gas

Problem solved. There is no filter on my carb, there are just the two screens that are in the seats. The fuel lines were so bad that they were collapsing and breaking down and filling the screens in the carb. I replaced the fuel lines, cleaned the carb, and cleaned the anti-siphon valve. Thanks everyone for the help and input.

What screen are you referring to?

Glad you got it figured out...

 

[anthony10092]

Re: Boat Straving for gas

I forgot to mention that i put a new fuel/water filter and separator on. The screens that I am talking about are in the inlet of the carb and attach to the seats. They act as filters for each seat.