Author Topic: Fuel Pickup Problems  (Read 2765 times)

savage

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Fuel Pickup Problems
« on: October 19, 2010, 11:21:56 pm »
Hello Everyone,  First post - a troubling tale.

It was last July on a Saturday, and I had my 1988 Stinger 311 about 39 miles South of Freeport Texas, drifting some hot structure, with the engines at idle.
Suddenly the starboard engine quits.  Primer bulb was soft. We replaced the Racor fuel filter thinking that the filter was clogged, but could not pump fresh fuel to get it running.  Inspected all my connections, and it would not pump fuel.  Port side was fine, so I ripped one of the nylon Tees out from the dash drain system and improvised a feed from the port engine fuel line to fuel both engines off of one pick-up.  That worked well, and we brought it home at 40 mph.

Took it home, and found that the aluminum "straw" that is below the elbow out of the fuel pickup had broken off and fallen inside the tank.  (not) running on fumes.  My plumber friend fabricated a replacement out of a copper pipe and solder, and we ran many more trips. 

Last Sunday we were returning from a 90 mile trip, and five miles from the dock I see the port engine slow down and then die.  Could not keep it running for more than a few seconds, so we brought it up the creek on one engine, at about 7 mph.  After cleaning all the fish, washing the boat, and sending my guests home, I popped the fuel gauge mount and look for the twin straws.  I see the new copper one doing just what it should, and the original aluminum one is laying on the bottom of the gas tank.  Same failure as in July; but isn't it odd that after 23 years, that these two critical components would fail in the same fashion within three months.

Both components rusted away with white, powdery oxidation just below the steel elbow that threads into the top of the fuel tank.

So today I am looking for a 1/4" NPT pipe that is about 15 inches long.  Also looking for a reason why, and wondering if any of my Stinger brothers have faced the same breakdown?  Is this an ethanol-related failure?  I usually keep my tank full and ready for the next trip during the summer & fall fishing season, so more often than not, that connection has been immersed in fuel.  The marina sells Valvetec 89 octane gasoline and they get refilled at least once a month, and sell about 5,000 gallons a week, so I don't believe its contaminated or expired gas.  Anyone else face this trouble?  How did you fix it and how long ago?


savage

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Re: Fuel Pickup Problems
« Reply #1 on: October 20, 2010, 10:48:45 pm »
I went looking for 1/4" pipe nipple segments today in about 15" length, and the closest I got to that was 4".
But then I got to thinking - what about flexible plastic pipe on a hose barb?

Ace Hardware fixed me up with a five-foot length of PEX (cross-linked polyethylene) for under four bucks.
I had a hose barb that fits (1/4 NPT x 3/8" Brass Barb Male Thread) and I put the latest solution together tonight.
Used a heat gun to soften the PEX and ram it over the hose barb, and now that it's cool, seems to be air tight and really solid.
Slightly flexible, which is good for running while pounding, and at this cost - if I have to re-work it, I just won't order fries that day.   ;D

I did some research about the suitability of PEX, and while I wouldn't want to be drinking water through PEX after running through the gas tank, it seems to be up to the task of pulling my gasoline out, where it connects to the steel elbow, brass valve, and brass barb assembly and then into the rubber fuel line that goes to the outboard. 

In my research, it appears that ethanol is harmful to brass, much more so than MTBE or straight gasoline.  PEX gets soft and slightly permeable when exposed to fuels, but inside the tank under very low suction, it should do fine. 
Hope so anyway.  Wish me luck! 

ccstinger

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Re: Fuel Pickup Problems
« Reply #2 on: October 21, 2010, 05:41:35 pm »
From what I understand, if two different type of metals are connected without being insulated, they can corrode.  For example, aluminum and steel.  The parts that broke weren't of a different metal from the gas tanks, were they?