key west 1720 fuel problem

peterh

Recruit
Joined
Jul 21, 2008
Messages
1
I think either my in tank strainer and or check valve at the fuel tank is faulty. Anyone have any idea how to remove the "elbow" at the top of the tank? It's located under the center console via an access hatch. Thanks for any info!!
 

q-t

Cadet
Joined
Jul 8, 2005
Messages
11
Re: key west 1720 fuel problem

I recently had to remove the anti-siphon valve from my tank, after being towed in when it cut off fuel flow. My 02 1720cc has the elbow located pretty much under the access cover at about 3 o'clock. There were screws protruding through the deck which will tear up your hands if not careful. suggest removing them from the hatch access ring first, which will also give a little more room to work. I had to split the hose about an inch to make it easier to get off the nipple, then trimmed before reinstalling. Use a wrench to hold back on the square part of the fitting in order not to damage the fitting or tank, then using a 9/16 wrench, the anti-siphon valve can be removed. I threw mine away and replaced with a brass hose barb.
Hope this helps you out a little.
 

Boatdood

Seaman Apprentice
Joined
Aug 22, 2008
Messages
43
Re: key west 1720 fuel problem

QT gave you good advice on how to get the elbow out of the tank but a couple of words of caution are in order. First dis-similar metals will promote corrosion of the less noble of the two materials, therefore anything you screw into the aluminum elbow should also be made of aluminum. Second taking the anti siphon valve out certainly eliminates some problems but it's in there for a reason. Its purpose is to prevent a broken hose or fitting from creating a siphon action allowing fuel to collect in the bilge of the boat. Coast Guard specs require builders to provide this protection, but they also allow for a shut off valve at the tank instead. If you chose to remove the anti siphon I'd suggest an aluminum shut off valve. I've always removed the screen on the bottom of a pick up tube any time I have it out of the tank. My theory is that it is a filter of sorts, and hard to get to. If I have a filter in the system I want it to be easy to get to, which the external large capacity fuel filter in you boat is. It will do everything that screen on the tube can do, and then some. I don't see a purpose for the screen.
 

q-t

Cadet
Joined
Jul 8, 2005
Messages
11
Re: key west 1720 fuel problem

I agree with all you wrote, boatdood, and thanks. I didn't see a way to replace the aluminum elbow, though, and didn't have another anti-siphon valve to put in there; probably wouldn't want it anyway. I did put thread sealer on the fitting; will have to check it out later and watch for corrosion. In my boat, the only way I would get a leak in the bilge is for something to happen to the fuel line, and it is very heavy hose, still in excellent condition. I do keep an eye out for anything different, though, so hopefully if anything bad starts in the future I will be able to detect it early.
 

Buzzsflybox

Recruit
Joined
Oct 22, 2009
Messages
1
Re: key west 1720 fuel problem

Anyone having fuel feed problems to the filter-seperator/motor should NOT have to relive (And pay the big $ for Seatow and shop $) the horrors I experianced in the Fall of 08 and Spring of 09. I had TWO (2) problems at once and it drove Me, my Dealer, and the Service Rep in the home office in SC CRAZY !!
(1) The aluminium anti-siphon flow valve (Top of the tank fuel fitting elbow) was stuck OPEN, allowing the fuel from the filter/seperator to siphon back into the tank after shutting the motor off to fish, transport, or store. This DRAINED the fuel line and filter/seperator and made it a ***** to squeeze bulb the fuel lines full again.
(2) At the same time (Or close to it) a chicken or the egg scenerio happened, complicating matters 10X worse. The in tank fuel tube (With the mesh strainer attached) developed two (2) crackes, where it is attached to the fuel tank/line elbow. This tube is a heat shrink material and was attached improperly at the FACTORY.
So be advised..... If it happened to me it could and probably happen again.
And the latest 08 previous posts were BOTH right on the money with the advice given about the difficulty in changing/reaching the elbow and anti-siphon valve. STICK WITH THE SAME metals for the previous post advise was right out of a metalergist's handbook!!!!!!
Hope this post helps and saves someone the nightmares I experianced.
Buzz
 
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