no fuel

[JV1964]

My mercruiser 350 engine has a fuel problem. As soon as I put her in the water she will run for about 5 or 10 minutes then shut down. I checked the see thru filter and can see that no gas is getting to it. Thinking it was the fuel pump I went ahead and changed it and went with an electric pump. She does the same thing though, run for a bit and shut down. It will run at idle speed on dry land for as long as I want. I drained the tank using the same pump and she ran for over and hour pumping gas out and nevre once did the pump quit. So I refuled her and put her in the water and yet again she will not run for more than a few minutes before I notice that no fuel is reaching the filter. I also changed the water seperator..I am stumped.. Can anyone tell me why this would happen?

 

[calwldlif]

Re: no fuel

Tank pickup?

 

[Don S]

Re: no fuel

OR the screen is plugged on the pickup or there is water in the tank that gets picked up when in the water.

 

[JV1964]

Re: no fuel

I thought of the pick-up or the screen, but why would it only happen when she is in the water. I can run it all day on dry land, at idle or at any position on the throttle. Now on the water she won't even idle once she starts acting up. If the screen or pick-up were clogged would it not do it on or out of the water?

 

[Don S]

Re: no fuel

Water or dirt collects on the bottom of the tank. In your driveway, you may have the bow down which puts all that junk to the front of the tank. In the water the bow is up and all the water and dirt is is in the back of the tank (WHERE the pickup is)

 

[JV1964]

Re: no fuel

Well that makes sense Don S. because she runsa fine in the driveway. Ok so how do I go about cleaning that out. Does the tank have to come out?

 

[Don S]

Re: no fuel

I just raise the bow so all the "Gunk" goes to the back, then pull the pickup tube out (make sure the fuel level is below the pickup). Use a remote electric fuel pump with a hose and small dia. copper tube and suck the junk out of the bottom of the tank.<br />Clean the pickup tube screen and clean or replace the antisiphon valve.

 

[JV1964]

Re: no fuel

ok I see 3 hoses. One which is the filler hose. Then there are 2 more next to that one much smaller about 3/8 or maybe 5/8. I am guessing one is the feeder and one is the return, but I don't see how it would come out. They are both attached to an elbow but they seem to be attached to the tank from factory and are not removable. Then there is the small round cover for the fuel sending unit for the fuel gauge. Are some of these fixed or are all of them removable and allow access to the pick-up.

 

[Don S]

Re: no fuel

You don't have return lines on a carbed engine, you better have a 5/8" vent, and a 3/8" supply line to the engine, along with the 1-1/2" fill hose.<br />The 3/8" line should be attached to an antisiphon valve which is screwed into a 90° elbow fitting with a pickup tube on the end. It is screwed into the the tank with a pipe fitting (MOST OF THE TIME). Without seeing your fitting, I wouldn't bet money on anything the boat builders do anymore.

 

[JV1964]

Re: no fuel

OK Don I checked the hoses again and you are exactly right on all three counts..1 1/2 inch, 5/8 vent,and the 3/8 feeder line. Before I do this is it possible to run a line from the electric pump to a portable 5 gallon tank, and put the boat in the water to make sure that dirt is causing the problem. If she feeds from a clean prtable tank then she should have no problem running in the water much like she does in my driveway.

 

[milkyway]

Re: no fuel

In addition to the new pump that you bought, you will spend another $50 easy to buy and hook up a portable tank. Plus the time you will tow the boat both ways.<br /><br />You said that when you "refueled" the boat you noticed "no fuel is reaching the filter". Given what you found here, I do not need any more proof that there’s something clogging your fuel system from the bottom of the tank to the fuel filter. That must be less than 4 feet distance. Listen to the advise the're giving you, it's will cost you nothing. Whether or not the boat runs on portable, you will still go back to the same pickup tube to find and fix the same problem. You won't spend an hour removing few screws and turning the elbow. <br /><br />You may need pipe sealant with teflon when you reinstall the elbow.

 

[milkyway]

Re: no fuel

Imagine if that tank is disconnected while you're cruising.

 

[JV1964]

Re: no fuel

OK guys. I will take the elbow off jack up the boat so all the junk goes to the back and try to clean it all out. Thanks for all the advice and I will re-post and let you know if this did the trick.

 

[JV1964]

Re: no fuel

Thanks for the advice guys.. Couldn't imagine how much junk i sucked out of there. She doesn't stall anymore.. Now it seems to get to much gas..lol...or not enough cause she won't run over 2000 rpm or 10 mph..anymore than that and she bogs down and tries to shut down, she will continue to run if I pull back on the throttle and run at or under 2000. Boats..u gotta love em..lol

 

[Gary H NC]

Re: no fuel

After cleaning the tank did you replace your water separator and fuel filter again?<br />It would be a good idea.<br />Plus the carb could be full of crud too..

 

[milkyway]

Re: no fuel

You should also empty out the tank of any old, dirty fuel and pumped fresh fuel. You might also have lots of water from the old fuel even though you did some refueling last time.

 

[JV1964]

Re: no fuel

yes I emptied the tank completely. Then I replace all the filters including the water separator. I am thinking that maybe the carb will have to be taken apart and cleaned out. In any case I found another problem. It seems that when I tested it yesterday in the water I noticed water getting into the bilge area. I inspected it closely and found that it is coming in from a small hole in the outdrive. It is about an inch in diameter and lies next to the exhaust pipe.. There are 2 of these holes. I was told that it sounds like the exhaust relief and is a simple fix once the engine is out of the way..Is there any way around this? I hate to think that the engine has to come out.

 

[Bt Doctur]

Re: no fuel

http://i57.photobucket.com/albums/g219/BtDoctur/87f8c3ab.jpg <br />can you identify the leak location from here

 

[JV1964]

Re: no fuel

Ok it looks similiar to the small hole next to the larger hole which appears to be the exhaust outlet. The small 1 inch hole right next to it. I can just barely feel a pipe from inside the engine compartment, and it seems to line up with the hole on the outside of the outdrive. This pipe feels like it is rusted.