fuel tank /feed disorder Still !!!!!!

guglielmo6160 · Post by **guglielmo6160** » Wed Jul 08, 2009 9:58 pm

ok, I still have a problem with my foward tank, as in its full, but for some reason the fuel pump cannot draw from the tank, I guess its like trying to suck on a straw thats plugged in the end, all is fine if I use only the rear tank my question, does anyone know if its possible to remove the feed , tube, from the tank, it seems to be about maybe a foot or less from the floor above it
and does anyone know what the inside of that looks like, is there a strainer? or is it just a tube going to the bottom of the tank?

as some of u know this has been an ongoing problem with this and finally narrowed it down to the forward tank,

rossjo · Post by **rossjo** » Wed Jul 08, 2009 11:06 pm

At the risk of being "Mr. Obvious" - have you tried blowing it out backwards (from the engine) into the tank to remove whatever is blocking it? If so - then disregard this useless piece of advice ...

guglielmo6160 · Post by **guglielmo6160** » Thu Jul 09, 2009 3:43 am

I actually thought of that , but still want to know whats doing it,, but I may do that,,lol

Paul · Post by **Paul** » Thu Jul 09, 2009 7:21 am

You should be able to undo the fuel line at the tank and spin the fitting/pick up tube out to inspect it. While you're there, check the anti-syphon valve. Quite often debris from the bottom of the tank will get trapped by the spring inside this valve and retrict flow.

Hope this helps,

Stripermann2 · Post by **Stripermann2** » Thu Jul 09, 2009 8:16 am

As Paul mentioned. Check the anti syphon valve, easily removed and cleaned. It'll do just as you described. Be sure also to keep whatever tank you're not using, closed off at the fuel manifold.

mtwolf · Post by **mtwolf** » Thu Jul 09, 2009 8:46 am

The pick up tubes, on my 73 F-31, are just that. Tubes. No strainers, just plain straight tubes. I found the rear tank tube was scaled shut when I replaced my fuel tanks. I was only running on the front tank which feeds the starboard engine first. I could run about a mile and the port engine would shut down do to lack of fuel. While I had the tubes out I plugged the end and then filled the tubes with carburetor cleaner. Let them soak awhile and then blew those out. If you have the original tanks it's a good possibilty that the tanks are full of crud.

1967 seavoyager · Post by **1967 seavoyager** » Thu Jul 09, 2009 10:43 am

If you still have the glass bowl fuel filters, take off the bowl & pull out the wafer assembly & take the wafers apart to clean them. Clean the housing & put it all back together. It worked wonders on mine. They filter better than they look like they would.

Dan Faith · Post by **Dan Faith** » Thu Jul 09, 2009 12:14 pm

Just curious where is the anti-syphon valve? I would like to know just so I can check mine.

Stripermann2 · Post by **Stripermann2** » Thu Jul 09, 2009 1:19 pm

Dan Faith wrote:Just curious where is the anti-syphon valve? I would like to know just so I can check mine.

If you follow the fuel line to the tank, it'll thread into another fitting, which in turn, threads into the pick-up pipe.
This fitting has a spring and check valve in it and can clog with varnish and crud.

The purpose of this fitting is for safety. If you were to rupture a fuel line, there would not be enough suction to overcome the spring and check valve, thus cutting off fuel supply from the tank. Do not eliminate or bypass this device.

Dan Faith · Post by **Dan Faith** » Thu Jul 09, 2009 1:53 pm

Thanks, I have to work on my sending units and I will do PM on all these at that time, it looks pretty easy and needs to be added to my yearly
maintenance list.

guglielmo6160 · Post by **guglielmo6160** » Thu Jul 09, 2009 8:34 pm

as mtwolf mentions I have no valves or strainers or anything, just pickup tubes , so Im assuming the foward tank pickup is clogged
everyone keeps mentioning anti siphon vlaves but there is nothing there except a pickup tube and a valve diredtly after that

mtwolf · Post by **mtwolf** » Thu Jul 09, 2009 8:59 pm

Bill,

My 73 doesn't have the anti-siphon valves either. It is an excellent idea to keep the fuel from flooding the bilge if the gas line were to break though.

John
F-31

prowlersfish · Post by **prowlersfish** » Thu Jul 09, 2009 9:06 pm

Bill a lot of pick up tubes have screens on the ends. remove the screen its not needed . you can also put a notch in the end of the tube so there will be less of a chance of somthing pluging it ( like the foil from a fuel aditive cap lol)

guglielmo6160 · Post by **guglielmo6160** » Fri Jul 10, 2009 12:14 am

thanks, all good advice, will take this thing apart early next week, Im sure its going to be straight foward. I was just concerned that I wasnt going to be able to remove the pickup tube , from where its located, but maybe its flexible enough to get it out without an issue

prowlersfish · Post by **prowlersfish** » Fri Jul 10, 2009 6:48 am

Bill won't your back deak come off ? Or is it covered with teak ?