Fuel tank outlet removal problem

[lrg355]

I had about 3/4 tank full of old 2 stroke mix in the tank of my project boat.  Removed the sending unit to have a peek inside.  Couldn't see much except 3/4 full tank.  Decided to siphon it out. Put a hose on the fitting, ran it thru transom drain hole to a 5 gal can.  Had a few cans ready.  Tank is 24 gal.  Tried to siphon it, no luck plugged tight.  Tried to blow in, no luck, plugged tight.  Put the hose in the sending unit hole and siphoned about 15 gal.  So the pickup tube is blocked or has some type of valve or filter that is blocked.  Ok, now try to take out pickup tube and elbow fitting on top. No luck again.  Time to look at YouTube to see how this disassembles.  It shows that the top elbow fitting should screw out of the " sleeve" fitting on the tank.  

Cleaned it up, put on AeroKroil penetrating fluid. Waited a few hours.  Held the 1 1/4 nut and tried to unscrew elbow fitting. No luck, stressing it to the point of breaking something so I now hesitated.  Does anybody have any experience with this fitting and pickup tube removal?   This is a poly tank made by Kracor.  This is on a 1985 Sea Nymph 195.

Edited March 12, 2023 by lrg355
Added pictures

[Frogger]

I’m wondering if it’s an anti siphon device, I think I had one on my tank when I tried to drain it. Can you put a line on it with a primer bulb and pump gas through it when you squeeze the bulb?

[lrg355]

Looked further online

 Some have just the tube but some have a filter on the end of the tube.  It looks like the filter that is in the gun of an oil burner,  sintered.metal. I have one in my Beckett oil burner gun.  Also used as mufflers on air line exhaust. There is probably one on the tip of my pickup tube.  Got to get the pickup tube out without ruining the tank.  I've tried blowing in with 80 psi air. No luck.  Must come out

[MADDIE]

i my be wrong but it looks like that fitting would have a nut on each side locking it in place on the tank .you may have to go in through the sending unit to undo it. i would try to loosen the nut  with out turning the pipe fitting.

[sherman brown]

Most old hoses have an inner layer that can separate and clog the line. on my Mercruiser, it ran ok at low rpm but when I tried going faster it just wouldn't go. then it sat for a couple of years and I tried starting it but it wouldn't start. so, I got my inline cheap electric fuel pump out and hooked to the line going to the tank but didn't get gas.

 

I had taken the line loose at the fuel/water separator and tried sucking gas through with no luck then I tried blowing back to the stand but again no luck. I got on amazon and ordered a new below deck hose that ethanol won't hurt as I had been using ethanol gas as nonethanol gas isn't available anywhere near me that I know of. and replaced the line from the tank to the motor. from that point, I had no more problems getting gas to the motor. i pumped the old gas out as best I could and filled the tank with fresh gas and went to Erie.

 

it started out running great but going down the lake it took spells of running very rough to the point it almost died. but it only lasted for a short time and then started running great again but then it would start running rough again. we were on our 3rd tank before it stopped doing this. I think it was just the old gas left in the tank that didn't get pumped out.

 

my point is to try running a new line off the tank to see if the line is causing the problem. and once you get the gas going through the line and empty the tank take a hose and go down the sending unit hole or the pickup hole and go to the lowest part of the tank and try to get any remaining old gas out of the tank.

Edited March 13, 2023 by sherman brown

[Norm Moser]

Irg, I did mine a few years back and that 90 degree fitting has a check ball in it. as I recall it was by law had to be there so gas could not siphon back into the bilge when the boat was sitting more so on I/Os where the motor can sit lower then the tank. The check ball on them are prone to getting gummed up and sticking closed try  spraying some carburetor cleaner and a little WD40 it to it to free it up.  as far as getting it off good luck they can be a bear some times being aluminum and corrosion.

[lrg355]

10 hours ago, MADDIE said:

i my be wrong but it looks like that fitting would have a nut on each side locking it in place on the tank .you may have to go in through the sending unit to undo it. i would try to loosen the nut  with out turning the pipe 

 

More searching online adds a bit more information.  That large 1 1/4 nut is holding the bushing or sleeve in place.  The OD of the bushing is 3/4 thread.  The ID of the bushing is 3/8 NPT female thread.  The opposite end of the bushing is flanged, about 1 1/4 Dia with two flats machined on the flange.  That is inside the tank.  There are two protrusions molded into the tank that the flats on the inner flange fit between.  That is what keeps the bushing from rotating.  I an getting about 15 degrees of rotation of the bushing now after being excessive on trying to unscrew the elbow fitting.  Had very little rotation of the bushing when I started.  The elbow fitting is 3/8 Male NPT threaded into the bushing with 1/4 female NPT out to the motor as you can see in the picture. Inside the tank and inside the 3/8 NPT Male end of the elbow is a barbed fitting with a plastic pickup tube to the bottom of the tank. This pickup tube and elbow fitting is very available online. Some tubes have a screen on the end and some have a sintered.metal filter while others have nothing. Mine obviously has something that is severely plugged. Cant find any ordering info on the sleeve. Problem is 38 years of corrosion etc and aluminum on aluminum galls up the treads.  Going to take the tank out and get all gas out and clean out to get all possible fumes out.  Last resort will be to CAREFULLY drill down thru the top and step drill up to near the diameter of the tap drill for a 3/8 NPT. Since there is a hole in the middle, the drilling should stay concentric.  With a thin wall from the now larger ID to the threads, it should collapse and break free.  Wish me luck!!

 

[Norm Moser]

Irg you are right that 90 threads into that nut on the tank, the 90 is what needs to get freed up when I looked on line a guy used a mix of acid tone and transmission fluid put it around the fitting and let it sit for a day and that loosened it up. I used CLR on mine as I recall just on the outside of the 90 where it threads into the nut. when you do get it out measure the tub so you can cut the new one to the right length.

[Frogger]

Irg, what reason again do you feel the need to remove this? Meaning I read your part where you say it’s plugged but I was thinking it’s because you were trying siphon from it or blow air back into it. Have you tried to pump gas from it like normal with a fuel line bulb?  

[lrg355]

15 hours ago, MADDIE said:

i my be wrong but it looks like that fitting would have a nut on each side locking it in place on the tank .you may have to go in through the sending unit to undo it. i would try to loosen the nut  with out turning the 

 

Put a long wire wrap into the elbow tube this morning.  It went around the corner and about 6 inches down, so no ball valve in the elbow fitting. Tank is about 8 inches deep.

Plan A was to get the fitting and tube out without damaging the tank.

That failed!  Tube is completely blocked.

Plan B was to get more aggressive with compressed air to 120psi and pulse it if necessary.

 

Plan C. Drill a .159 hole on top center of the elbow and put a 1/8 or 5/32 rod down and poke out the obstruction.  Than, tap the hole for 10-32 and put a plug in it.

 

Plan D  Drill the elbow fitting out as previously described.

 

Luckily , plan B worked. Plumbed the compressor directly into the 1/4 NPT elbow .  Turned the valve on at 80 psi, cranked up the regulator and it let go at 100psi.  I think there  may have been a completely plugged screen in the tube. I am going to take the tank out for a good cleaning. Lots or rubber particles in there,  probably from the dry rotted looking fill hose.

FINALLY SUCCESS!

Thanks for all the input from everyone.