I run out of gas when half full

[mwnitz]

My boat runs out of fuel around 10 gallons, yet according to the manufacturer I have a 20 gallon tank! it has been doing this ever since I owned it, but I thought I had a 10 gallon tank. My gauge reads full when topped off. When I am close to the 10 gallon mark the gauge swings between full and half, which I believe is normal fuel slosh back and forth. I suspect whatever tube that is inserted into the fuel tank isn't low enough, if that is possible. Can someone help me diagnose this condition? My fuel tank is plastic and under my floor, but has an access panel above the fuel tank. Thanks.

 

[Fishermark]

Re: I run out of gas when half full

My fuel tank is plastic and under my floor, but has an access panel above the fuel tank. Thanks.

The only thing to do is to pull off the access panel and look. You can remove the sender by removing a few screws. It is possible you have a short tube - or maybe a tube with a hole in it - or maybe a 10 gallon tank.

 

[rodbolt]

Re: I run out of gas when half full

or someone installed the tank with the draw tube at the fwd end.
happens.

 

[777memaw]

Re: I run out of gas when half full

I had this problem I had a hole in the pickup tube the tank had two tubes all I had to do was move the line to the other one.

 

[zbnutcase]

Re: I run out of gas when half full

Sounds like a draw tube issue to me, time to remove it and have a look!

 

[mwnitz]

Re: I run out of gas when half full

I will have a look when I get low in fuel. Does anyone have a link to a picture of what this looks like?

 

[Bondo]

Re: I run out of gas when half full

Does anyone have a link to a picture of what this looks like?

Nope, but at the end of the fuel line is an Elbow, unscrew it from the tank,+ the diptube comes out with it...

 

[elkhunter338]

Re: I run out of gas when half full

You do not need to remove the sender, just fuel pickup tube.

 

[Alpheus]

Re: I run out of gas when half full

Are you sure its 10 gallons? I have a 35 gallon tank and it says on the tag 6 gallons are unusable...

 

[Willyclay]

Re: I run out of gas when half full

Just drained the old, bad fuel out of a 1995 Ebbtide 192SE that is tagged as 26 gallons capacity. Both the electric and mechanical gauges indicated "FULL" but we only got 20 gallons out before sucking air. Good luck with yours!

 

[tboltmike]

Re: I run out of gas when half full

If there is a leak in the fuel line and such air, at some point as fuel is used, the negative head increases to the point where enough air is sucked in to loose prime. Happened to me on my old carb truck with the mechanical pump on the engine. The hose to fuel tank connection aged and cracked. When a half tank it would loose prime at idle speeds.

 

[mwnitz]

Re: I run out of gas when half full

Aha! I found the culprit. The plastic pickup tube has a crack in it where it connects to the aluminum fitting at the top of the fuel tank. This part of the fuel tank is only half way to the top, thus I run out of fuel at the half way mark, 10 out of 20 gallons! Now, the question is what now? I keep hearing of problems with these plastic tubes. I saw a post about soldering a copper tube to the fitting, but the fitting in the post was brass. Mine's aluminum! What's the best way to go about this? Did I mention that I need the boat operational by Thursday morning?

 

[dingbat]

Re: I run out of gas when half full

No problem soldering copper tubing to a brass fitting

 

[Reel Kahuna]

Re: I run out of gas when half full

No problem soldering copper tubing to a brass fitting

That is, if you know how to solder

 

[mwnitz]

Re: I run out of gas when half full

Bit it's an aluminum fitting, not brass.

 

[tswiczko]

Re: I run out of gas when half full

make sure they are both clean and use flux paste, if you can find it silvalloy 60/40 and silvalloy flux are good for braz joining disimilar metals but you should be able to solder the copper to brass

 

[Willyclay]

Re: I run out of gas when half full

Bit it's an aluminum fitting, not brass.

Swap the aluminum fitting for a brass one and then solder a new hard copper pickup tube into it. Glad you found the problem. Will double-check mine now. Good luck!

 

[Silvertip]

Re: I run out of gas when half full

The draw tube looks and works like a soda straw stuck into a McDonalds drink cup. It sucks fuel from the bottom of the tank. You have two places to look. If what you see has a wire on it, that's the fuel gauge sender. If it has a fuel hose on it -- that's the fuel outlet and the dip tube is below that in the tank. Pull the entire fitting and the dip tube comes with it.

 

[sethjon]

Re: I run out of gas when half full

Pull out the tank. Empty it and then fill with water to measure the amount. Then you'll know for sure. I doubt you have a 10 gal tank in a boat your size. Its more likely around 18.

 

[mwnitz]

Re: I run out of gas when half full

I found the fuel withdrawal tube at Home Depot! A 25' of polyethelyne tubing cost me under $8! It looks identical to what I pulled out of the gas tank. I searched the high heavens for this item with no luck until I went to the Depot. I used a heat gun to remove the old screen at the bottom of the tube, and used a heat gun to fuse the screen together with the new tube. Thanks for all your input, everyone.