Ran out of fuel and now big problem - SOLVED

[LAC_STS]

Long time no see here. Been busy switching professions. Hello everyone.


Took the boat out and it was running perfect for about about 2 hours. We were just driving it up and down the bay and it was perfect. Then we started heading back and ran out of fuel about 30 feet from the dock. With the current and wind going out I tried to start it and start it just to get to the dock.

Well I ended up trying three ropes together and jumping in and swimming to the dock to pull the boat back to the dock. Then I put about 30 gallons in it and we went back out to make sure everything was still good and then this happened.

https://youtu.be/4EU5zABG_M8

The engine will run good for about 5 mins then it looses RPM and surges and will die if I dont put it into N quickly.


So far I have removed the pickup tube from the tank, valve and tube are good. Tank is clean. I changed the fuel water sep filter, no water in it just a little crud. I checked the tank vent - good, removed the fuel line and fitting from the carb to see if there was a screen in there, nope no screen. I removed the hose at the tank and at the carb and blew in it at the tank end and blowing through the fuel water sep filter it blew fuel out the carb end with not that much effort.

so I'm left with the carb I guess. This def seems fuel related to me.


Another thing Im going to do which I should have done first is Im going to take the boat out and have my girl get it up to speed and then watch down the throat of the carb while it does this and see if the fuel looks like it differs. As in if the jets stop spraying or whatever. Then I can verify 100% that its fuel related although I am pretty sure it is.


What do you guys think?

 

[Bondo]

Ayuh,..... Why are ya revin' the snot out of it in neutral,..?? That proves Nothin',.....

How 'bout the fuel pump,..?? No mention of it, or it's proper function,....

 

[Tnstratofam]

I had this same problem three summers ago. Narrowed it down to my antisyhpon valve or my fuel pump as bondo mentioned. I drydocked the boat for a resto and am going to replace both those parts before I put her back in the water hopefully next spring. My engine is an omc 350 chevy with a cobra outdrive and would also run fine and rev good with no load on her in neutral. However put her in the water and she would stumble and fall flat on her face if you tried to accelerate.

She would die within about 10 seconds of stalling out. She would start right back up but no power. I pulled my fuel system apart and couldn't find a culprit. Everything was clean and no water in it to speak of. The only other thing I didn't try that was suggested was the accelerator pump in my 4 barrel, replacing my antisyphon valve, and checking my fuel pump.

Like I said I pulled her into the garage without fixing my fuel problem so I still have that on my list of repairs once my deck is finished.

 

[LAC_STS]

Ayuh,..... Why are ya revin' the snot out of it in neutral,..?? That proves Nothin',.....

How 'bout the fuel pump,..?? No mention of it, or it's proper function,....

That's in gear Bondo. That's me driving it

 

[LAC_STS]

Fuel pump is new about a year ago. I checked and it seems to be working fine.

 

[LAC_STS]

In the video the trim gauge doesn't work nor does the speedo. And once the RPMs hit just under 4K I stop touching the throttle. It does the rest on it own. That was a quick one. Usually it will run fine at 4K RPMs for like 5 mins and then do that.


Sorry for the confusion

 

[Bondo]

Ayuh,.... Still sounds like it's runnin' outa gas,.....

A new fuel pump, is an old fuel pump, if it's fulla crud, 'n not supplin' good fuel as required,....

 

[LAC_STS]

Ayuh,.... Still sounds like it's runnin' outa gas,.....

A new fuel pump, is an old fuel pump, if it's fulla crud, 'n not supplin' good fuel as required,....

Ok so is there any way to check if there is crud in the fuel pump? I haven't tried it while it's messing up but when it's idling there is good pressure going to the carb.

I know there is a little screen in the inlet to the pump but can I take the pump apart? It's a carter electric pump. P4070 style if I remember correctly.

 

[LAC_STS]

Ok so is there any way to check if there is crud in the fuel pump? I haven't tried it while it's messing up but when it's idling there is good pressure going to the carb.

I know there is a little screen in the inlet to the pump but can I take the pump apart? It's a carter electric pump. P4070 style if I remember correctly.

Never mind I just found my old one and took it apart and saw the screen inside and all that. I will check that in a couple days when j go to the boat.

 

[LAC_STS]

Took the fuel pump apart. Looks brand new. Not even a bit of anything on the screen that was inside.

So guess I'm at the carb. I took it off. Gonna I open it up and see if it's got anything in it.

Other than that I'm at a loss.

 

[LAC_STS]

Took the carb apart. Looks like a band new card. No gunk in it. Floats are adjusted correctly. Everything looks good.


At a loss now. Will hook the carb back up and try it all again and see what happens. It's weird because it ran perfect all day until I ran out of fuel.

 

[skippy2235]

what is the fuel pressure? should be 4-8 psi. They burn up quick when run dry.

 

[LAC_STS]

what is the fuel pressure? should be 4-8 psi. They burn up quick when run dry.

I will check it again tom hopefully. It was 6.5 ish last time I checked. I lost my tee fitting thing I had made for it so I have to go buy / build a new one. Hopefully have some results tom.

I'm also going to bring somebody to drive the boat while I look down the throat of the carb. Want to see if I see the fuel spray change or stop when it happens. I figure that will tell me for sure if it's fuel related although I can't see how it wouldn't be fuel related since it ran perfect until I ran out of fuel.


Thanks for the help everyone.

 

[user-name]

Let me get this strait .

Ran great.
bought new gas runs Bad.

My math comes up you bought bad gas.

Hook up a portable tank with fresh gas to the FP and see what happens

 

[southkogs]

Any chance you've got a problem with the throttle itself? Maybe a cable slippin' or somethin'?

 

[LAC_STS]

Let me get this strait .

Ran great.
bought new gas runs Bad.

My math comes up you bought bad gas.

Hook up a portable tank with fresh gas to the FP and see what happens

No. I went out for about 3 or 4 hours and the boat ran perfect. I was just driving it up and down Sarasota bay cruisin. I knew we were running low on fuel so we headed back into my marina to get some fuel. We ran out of fuel about 30 feet from the dock but the wind and current were blowing us away from the dock. So I tried to start it again and again and it would start for just a second then die. There was 0 fuel left.

I ended up getting it back to the dock with help from some nice guy that lives by the marina and has a dock in his back yard.

So I went and got 5 gallons of fuel in a can and put it in. Then ran the boat to the gas station that has on the water fuel. Put about 30 gallons in her.

Went right back out into the bay and this is when it started doing this. The video was a quick one. Usually it will run great for about 5 to 10 mins then it does what it showed in the video.

I changed the fuel water sep filter first of all and then I took the sender out of the tank and looked down in there and the fuel looks and smells fine. No water in the tank. There was a piece of a zip tie in the tank somehow but I took that out with a grabber.

So Im 99% sure the fuel is good. It seems to me that running out of fuel messed something up. But so far I have taken apart and tested everything from the tank to the carb.

Going to hopefully put the carb back on today and have the marina splash it and take it out and see if it still does it but this time Im gonna look down the throat of the carb to verify if its fuel related and I built another fuel pressure tester rig with clear hose section and all. So Ill hook that up too and see what pressure Im getting.

 

[LAC_STS]

Any chance you've got a problem with the throttle itself? Maybe a cable slippin' or somethin'?

I dunno. I replaced the throttle cable about a year ago. When the problem starts happening I am not touching the throttle. So I dunno. I did check the throttle cable at the carb and it seemed fine and adjusted correctly. I havent checked it at the shifter but to me it really doesnt seem like its the throttle cable.


I think number one is I need to get my girl to drive the boat while I look down that throat of the car and visually check if fuel related or not. Then I will know 100%

 

[LAC_STS]

http://www.youtube.com/watch?v=uydK2gPGxlY

This is on the hose. I figured if the pump ran that meant it worked but it's only getting 2.5 to 3 psi. So wouldn't that make sense that once I get up on plane around 4K RPM that it will run good for 3 to 5 mins then it looses RPM and surges because the bowels in the carb are funning dry because it doesn't have enough pressure?


Sound right? Do electric pumps go bad like that where they will still work just not put out enough psi.

 

[Sparkinator]

Low psi could be the problem. My boat was doing the same thing of running for a few minutes and shutting down. I found a piece of trash caught at the anti-siphon valve. it would run fine and then eventually starve for fuel.

 

[LAC_STS]

Well I hooked an old elec pump up to see what would happen. Same exact carter pump. When I did it pegs my gauge at 10+ psi. Dunno if it's cause it's an old pump or what. I did open the top first and make sure it was clean.