Generator cuts out - only from STBD tank

importmonkey

importmonkey

Opinionated Member
Jul 9, 2015
1,056
Space Coast, FL
Boat Info
2005 260DA (sold)
2007 44DA (sold)
1989/2015 Hatteras 65c
Engines
12v92TA
So, I've been dealing with this issue on my genny for some time now. She runs like a champ when the fuel selection valve is on the PORT tank, but tends to shut down on her own if on the STBD tank. Not really sure where or how to start troubleshooting this issue (valve, pickup, et cetera). Thanks.
 
How much fuel is in each tank? The generator usually draws it's fuel from one tank. The fuel pick up for the generator is located at a higher level in the tank from the main engine. Therefore you can have enough fuel to run the main engine but not enough to run the generator.
 
plenty of fuel. seems to happen whether full or half/full of fuel. each tank has roughly (within 3 gallons of each other) the same amount of fuel.
 
Its either a valve or pickup issue since the filters are after the valve. As far as I can tell there are no shut offs on the tops of the tanks (as you probably know you can barely even feel up there never mind see!).

I have not looked at how the access is to the valve, but you could try pulling it out and either bypass it by connecting stbd tank directly or swap port and stbd lines (make sure you do both supply and return lines). If it works you know the problem is the valve, if not the problem is between valve and tank, most likely a clogged pickup.
 
An easy thing to check is whether the tank's vent is clogged, or not. If not sure by looking, remove the STBD tank fill cap and see if the genny runs better. There could be a slight blockage - not enough to cause the main engine to have a problem, but the smaller genny may not be able to pull through. Easy check, anyways - and eliminates a variable.
 
Lazy Daze said:
An easy thing to check is whether the tank's vent is clogged, or not. If not sure by looking, remove the STBD tank fill cap and see if the genny runs better. There could be a slight blockage - not enough to cause the main engine to have a problem, but the smaller genny may not be able to pull through. Easy check, anyways - and eliminates a variable.
Click to expand...


Ha! Even in the manual to check the vent screens. I'll take a look Friday.

If that doesn't work, maybe I'll dig into the selector valve panel.

Thanks guys.
 
took a look. the port side seems okay. not sure about stbd. couldn't lean down from the deck far enough to get a good look. any idea how to get those things out? do they turn out? would be easier to pull them out and check them top side.

manual says that it's imperative that you keep clean and in excellent repair - but not how
 
Investigated a bit. Fuel lines seem fine - from what I can see.

This is what my crossover valve looks like.
20180818_084224.jpg

20180818_084540.jpg


It does not look like the "Generator Fuel Crossover Board" in the manual. Can anyone else verify that's what theirs looks like?
generator crossover board.JPG
 
importmonkey said:
took a look. the port side seems okay. not sure about stbd. couldn't lean down from the deck far enough to get a good look. any idea how to get those things out? do they turn out? would be easier to pull them out and check them top side.

manual says that it's imperative that you keep clean and in excellent repair - but not how
Click to expand...

Vents are basically thru-bolted. There's a nut on the back side. But just try running the genny with the fuel cap off - that does the same thing as a clear vent. If not change, then most likely the vent is good.

The blockage might be enough to cause issues for the genny, yet not enough for the mains. This still may not be the issue, but it's worthwhile to check.
 
Mine looks like that....My wife pointed the "long" part of the handle toward the tank she wanted when in fact it is the "short" side of the handle that has a little pointer on it........It could be that simple........Hopefully
 
Mine looks like that....My wife pointed the "long" part of the handle toward the tank she wanted when in fact it is the "short" side of the handle that has a little pointer on it........It could be that simple........Hopefully
 
ASH said:
Mine looks like that....My wife pointed the "long" part of the handle toward the tank she wanted when in fact it is the "short" side of the handle that has a little pointer on it........It could be that simple........Hopefully
Click to expand...

This would be my guess. In post #9 the selector valve would be in the off position.
 
Yes post 9 the tank indicator is pointing to off......there is nothing wrong with the vents or lines....You are reading the handle wrong.
 
ASH said:
Yes post 9 the tank indicator is pointing to off......there is nothing wrong with the vents or lines....You are reading the handle wrong.
Click to expand...

Ugh.

Sorry to mislead you.

Yes. I'm aware of the pointer and I realize the selector is in the off position in the picture. I had it there for all of 10 minutes while i removed the panel to inspect behind there.

I always leave it to port (180 degrees from the picture) when running. If I put the long part of the handle "down" (pointer going to stbd) it won't run long.
 
If the lines are not to difficult to get to I would consider swapping the port and starboard fuel lines (both feed and return). If the problem then moves to the port tank you know you have a problem with the cross over valve.
 
Good thought. Think I'll wait til fall to do more invasive troubleshooting. Something about breaking apart the connections to that valve scares me a bit.

Anyone have a diagram of the valve and how its supposed to work? Why 6 lines? I understand 4, but 6? Are two for breathers? I also would have expected to see three - PORT, STBD, and OUT.
 
importmonkey said:
Good thought. Think I'll wait til fall to do more invasive troubleshooting. Something about breaking apart the connections to that valve scares me a bit.

Anyone have a diagram of the valve and how its supposed to work? Why 6 lines? I understand 4, but 6? Are two for breathers? I also would have expected to see three - PORT, STBD, and OUT.
Click to expand...

Supply and return for both tanks = 4 supply and return for gen. = 2
 
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