Water moisture in the tank?

[mbowers]

Sounds like an air leak as discussed. Water in the fuel is not good and saltwater is terrible. I blame bad vent placement for two damaged motors of mine. The vented caps are terrible. A proper vent line should go up vertically and then have 2 full vertical loops in it before it goes down to the tank. Any water that does get past the upward run gets trapped in the loops and should evaporate without getting to tank.

My redesigned vent with double loop system.



The soft B1 fuel lines should use radial head tie wraps not the cheap flat ones. Even the good SS clamps easily cut those B1 hoses. Clamps on A1 hose should be solid ABA or AWAB clamps and not cut into line like below



Should replace fuel lines every 5 years and it should be easy to do as just attach to old line and pull new one through. You might find way too much line and the wrong grade was used like on my new boat. 21ft of B1 hose under deck for 12ft run on an 18ft boat! I replaced with 14ft of A1 as is safe for fire resistance below deck.



Shouldn't really use tape on threads as any little bits that come off can pass filter and clog injectors. Paste sealants are better. https://www.jamestowndistributors.c...to+Properly+seal+Fuel+Fittings+and+Fuel+Lines

Please post pics of various components so we can help you get everything right. Most boat builders build crap because they can get away with it and most mechanics make it worse. Not all, just most!

 

[Rockfish]

Interesting article on the Teflon fuel tape and worth pondering. Have never had a problem with it myself on the threads for the cut off valves etc. but now I wonder if I should use the liquid method. I do know a lot of people use the tape. Any small bit that breaks off and manages to get into the fuel flow would have to pass both the Racor and the large fuel filter on the main before it could get to an injector and those filters are stopping the 35 years of crap that gets stirred up in my tank, however the author says it happens. I wonder what the motor/boat manufacturers recommend. I do run Seafoam through the fuel system when I notice any hesitation at all in the direct injected main motor and it cleans it right up.

Was looking at the picture of the old crap fuel line you replaced and you are right, it looks like the owner before you used a super cheap auto type hose clamp, rather than a high end, all stainless marine type clamp that does not cut into the fuel line, distributes force equally around the circumference and costs a fortune by comparison.

 

[triplenickel]

I would think properly applied tape is fine, when I say proper I mean have it start a thread or 2 back not overlap and hang over the face partially covering the port where the overlap will be cut off during threading in.

From the article; clogging in the first tiny micron orifice it encounters, if not the fuel pump then an injector

In my experience there's still another filter between the last connection any of us would usually touch and pumps and injectors anyways.

 

[mbowers]

Interesting article on the Teflon fuel tape and worth pondering. Have never had a problem with it myself on the threads for the cut off valves etc. but now I wonder if I should use the liquid method. I do know a lot of people use the tape. Any small bit that breaks off and manages to get into the fuel flow would have to pass both the Racor and the large fuel filter on the main before it could get to an injector and those filters are stopping the 35 years of crap that gets stirred up in my tank, however the author says it happens. I wonder what the motor/boat manufacturers recommend. I do run Seafoam through the fuel system when I notice any hesitation at all in the direct injected main motor and it cleans it right up.

Was looking at the picture of the old crap fuel line you replaced and you are right, it looks like the owner before you used a super cheap auto type hose clamp, rather than a high end, all stainless marine type clamp that does not cut into the fuel line, distributes force equally around the circumference and costs a fortune by comparison.

That was the boat builder who used that clamp and the unsafe B1 grade fuel line. I spent obscene money on that boat because I had an older one and it was so well built by previous owner of company. New guy bought the company and dropped the quality to terrible!

I bet motor manufacturers recommend the paste sealants too. Same thing for hydraulic steering from Seastar: no tape!

I wouldn't blow off a trip to get rid of Teflon tape in fuel system but I would try to change it next annual service..

 

[Cabezon1]

Had the boat out on the water yesterday after changing one of the primer bulb-same problem. Starboard engine would bog down/and shut off at trolling RPM.squeeze the primer bulb and was able to start the engine again. I am now convinced it is not moisture in the tank. Checked the recently changed fuel/watrr filter. All seems
Good. Maybe it is the fuel injectors being dirty so I put some yami ring free in the tank hoping it might clean them up. Today the situation was even worst. The engine actual bog down while on plane. Try to squeeze the primer bulb again but this time it wouldn't even stay hard. No fuel was reaching the bulb. Now I am thinking the problem lies between the bulb and the tank. One of the marine techs suspect the anti siphon valve might be malfunctioning and should be cleaned or replace. My question is if I run a twin engine boat, does that mean I have two anti siphon valves at the tank? If there are two valves, chances are the starboard engine's valve is likely to be the cause of it being bog down?

 

[GLG]

It sounds like you are sucking air into the system. You need to isolate what part is causing the air to get in and replace that part.

As you probably know the fuel pump and the primer bulb both work on a vacuum principle. They both create a vacuum that draws fuel from the tank through the tank pickup tube or tubes, fittings, lines and filters. If you have air entering the system at any point you will not create a vacuum and cant get fuel to the motors. The first step is to isolate where the problem is by removing or bypassing, temporarily, parts from the circuit. Most often the first thing to do is hook up a portable tanks to the motors and see if that works. This way you can rule out if its at the engine or somewhere else. From you other post it seems that you have two filters so I would suspect that the problem is between the tank or the filters. To confirm you could put your two portable fuel tanks on the inlet side of the fuel filters and test. That way you would rule out that part of the circuit. Work backwards until you find the problem point in the circuit. If you don't have two portable tanks you could test each system separately with just one tank.

When an anti siphon valve goes it mostly gets stuck closed and your bulbs will collapse. That's not to say that they could also start leaking air from corrosion too. On my last boat I had two pickup tubes in my tank, one for the main and one for the kicker and I suspect you may have two also with that much HP back there. Hope that helps.

 

[Rockfish]

GLC’s idea to run a portable tank test would definitely rule out any motor issues and help test down the line to eliminate connections as problems. However if your Yami 225 is anything like my Merc 225 there is no quick connection. The fuel line is plumbed directly deep into the motor and takes some messing around to disconnect and connect. Again if like mine I would use a brass fuel line connector and two clamps and disconnect the last bit of fuel line going to the motor and connect to it as that would be easier.

There is a lot of good info in this thread and to summarize:

Check for air leaks and redo connections to prevent loss of vacuum and possible vapour lock. Any component in the system could have an air leak associated with it or its connections and a line could even have a small hole it in although that could well cause a fuel leak and gas smell.

Check for any physical blockage or partial blockage/intermittent blockage of fuel which could be in the anti-siphon valve, the fuel lines or in the down tube in the tank and its screen, if it has one, or anywhere in the whole supply system. A blockage could even move a bit and cause intermittent blockage of various degrees

Check the vent and vent hose for a blockage or partial blockage because if air can’t get into the tank the fuel pump will give up after a while trying to suck out fuel against the increasing vacuum in the tank and the motor will fuel starve. Bug cocoon’s and spider web material for example is very tough and long lasting and can block the air vent system. Once the motor stalls out air can leak back into the tank, ending the vacum and the motor will restart. Perhaps one way to quickly test for this could be to remove the filler cap for a test to let in lots of air to the tank and see if the problem goes away. Have seen motors stalled out and portable red plastic tanks crushed and imploded like a crushed pop can because someone forgot to open the vent on the tank.

Have you changed the fuel filter on the motor, I know you did the Raycor?

 

[triplenickel]

Disconnect the line as close to the motor as possible and blow into the lines. You could also rig up a simple leak down tester, hose barb to one side of the run on a tee, gauge in the branch, ball valve to a schrader valve (looks like a valve stem on one side and 1/4 or 1/8 npt on the other) in the other run. If it's at the marina bring a bike pump, put a few psi in and see if it holds. If it leaks down grab a bottle of windex or soapy water and start spraying connections. The anti siphon valve is a basic check ball seated by gravity and if its passing at all you'll hear bubbles in the tank if you listen at the filler, this is easier if you have steady air supply from a compressor or a friend full of hot air. If it's the anti siphon pull it, clean it and lip test it again, could be a little piece of **** in there keeping the ball from seating. If you pull the valve out shake it and listen for the ball rattling.

If the delivery system checks out rig up check your fuel pump discharge pressure. Unlikely though as its both engines.

 

[Cabezon1]

To each and every members that has offered tips and advise. A thank you. I have learned a lot and hopefully will get to bottom of this soon and report back what my findings. If this happens to me I am sure it might have happened to others at one time or an other. I am glad to be a member of such a forum where advises and experiences are shared so generously.

 

[Franko Manini]

I'm wondering if your tank vent(s) are plugged. You can't move fuel out of the tank without replacing the lost volume with air. Simple test is to try running the engines for a bit with the filler cap off or loose. I realize this maight be tough on some boats.

 

[Cabezon1]

I'm wondering if your tank vent(s) are plugged. You can't move fuel out of the tank without replacing the lost volume with air. Simple test is to try running the engines for a bit with the filler cap off or loose. I realize this maight be tough on some boats.

That is unlikely because I run twin yamis and if tank vent is plugged wouldn't both engines be starving for fuel? Anyway, hooked up the portable tank to the engine that is giving me problems and it ran fine for 30 minutes until I shut her off. That rules out the motor so now I am work backwards from the primer bulb toward the tank. Looks more and more like it might be the anti siphon valve or pick up fuel lines that are blocked.

 

[noluck]

it is quite possible you have older fuel line not compatible with ethenal blend and is deteriorating. my friend's ski boat did this last year and we replaced the fuel line to the new A1-15 rating, newline hose has it in surrey

 

[GLG]

so now I am working backwards from the primer bulb toward the tank.

So for any good mystery story we need resolution. Have you tracked down the problem?

 

[Cabezon1]

And the saga continues. So after hooking up the portable tank to the engine, I was able to kind of eliminated the motor being the problem. Thought it might be the anti siphon valve or the fuel pick up line. Took the lid to the access hole off and started messing with the ASV. Unscrew the ASV and inspected the ball bearing-seems to work fine. Wasn't stuck. It might be the fuel pick up? So I tried to take it to out to see whether it was clogged but then realized it was welded to the fuel tank. WTF. Who would weld the pick up line to the tank? Apparently Grady White does. Now I am getting really frustrated. Googled to confirm and some how stumbled upon a lay out of the Grady white islander. The light came on. I have been messing with the wrong tank. All the time I thought I was working on the main tank turns out it was the auxiliary tank. I felt like an complete idiot. Today we lifted the deck and exposed both the aux tank and main tank. Took out the AVS to the main tank and inspected it to be in good order. Then we used an air compressor and blasted some air into the tank through the pick up line hoping it would clear any blockage. Gasoline started to rush out and out came a piece of black rubbery debris. How it got into the tank I have no idea. But I think we have found the culprit. It was partially blocking the stbd motors pick up line causing fuel starvation from time to time. I hooked up the fuel system and ran the boat out to where we were soaking our prawn traps. No problem and the
Engine engine ran perfectly . I think I might have fixed it. Knock on wood. The next step is to run the tank dry and try to suck any debris out via the sender opening. Hopefully it will solve the problem for good. Sorry for the long story but it was,to me anyway, a very long process.

 

[noluck]

And the saga continues. So after hooking up the portable tank to the engine, I was able to kind of eliminated the motor being the problem. Thought it might be the anti siphon valve or the fuel pick up line. Took the lid to the access hole off and started messing with the ASV. Unscrew the ASV and inspected the ball bearing-seems to work fine. Wasn't stuck. It might be the fuel pick up? So I tried to take it to out to see whether it was clogged but then realized it was welded to the fuel tank. WTF. Who would weld the pick up line to the tank? Apparently Grady White does. Now I am getting really frustrated. Googled to confirm and some how stumbled upon a lay out of the Grady white islander. The light came on. I have been messing with the wrong tank. All the time I thought I was working on the main tank turns out it was the auxiliary tank. I felt like an complete idiot. Today we lifted the deck and exposed both the aux tank and main tank. Took out the AVS to the main tank and inspected it to be in good order. Then we used an air compressor and blasted some air into the tank through the pick up line hoping it would clear any blockage. Gasoline started to rush out and out came a piece of black rubbery debris. How it got into the tank I have no idea. But I think we have found the culprit. It was partially blocking the stbd motors pick up line causing fuel starvation from time to time. I hooked up the fuel system and ran the boat out to where we were soaking our prawn traps. No problem and the
Engine engine ran perfectly . I think I might have fixed it. Knock on wood. The next step is to run the tank dry and try to suck any debris out via the sender opening. Hopefully it will solve the problem for good. Sorry for the long story but it was,to me anyway, a very long process.

that black crap is the fuel line coming apart, time to change the hoses. the new hose will have a ethanol rating http://www.new-line.com/hose/automo...-uscgce-marine-fuel-line-sae-j1527-type-a1-15 this is the newest and is E15/B20 rated

 

[Cabezon1]

I think I can finally put it to rest now. Turns out it was an engine problem. Changed out the low pressure pump(fuel pick up) but that didn't help. Maybe the fuse to the LP was blown. Nope. Problem did not go away until I changed the "F" filter and the inline pressure relief valve right above the fuel pick up pump. Now the engine is running smooth and not stalled the last 3 trips out. Extremely satisfied to have learn something new and saved myself some coins.

 

[staying alive]

I kept my tanks full over winter on the trailer to stop condensation, but with the last hot spell the fuel would expand and come out the vent tubes on my Crestliner Eagle , not nice as it blistered my paint below the vents.
Cracked the fuel cap a bit the let the pressure off .
Just have to remember to not have a smoke around the filler and vent area.