Fuel Tank Issue

[Roho]

Grady-White.com fuel management

 

[SkunkBoat]

How do I get sucked into this?
Hookup, if you’re facing the stern then the left one is starboard

There is no Both on the valve. Centered is Off.

You cannot run one motor on two tanks at the same time.

Each valve is for one motor selecting either tank.

It CANNOT be one tank selecting either motor

 

[Hookup1]

How do I get sucked into this?
Hookup, if you’re facing the stern then the left one is starboard

There is no Both on the valve. Centered is Off.

You cannot run one motor on two tanks at the same time.

Each valve is for one motor selecting either tank.

It CANNOT be one tank selecting either motor

That view is from the back of the boat lookin forward. Port is left side. The valves are inside the compartment on port side.

That reference to center position being both tanks was something someone else said-possibly another thread. Not sure what that position does but I’m not planning on finding out.

 

[SkunkBoat]

That view is from the back of the boat lookin forward. Port is left side. The valves are inside the compartment on port side.

That reference to center position being both tanks was something someone else said-possibly another thread. Not sure what that position does but I’m not planning on finding out.

wasn't sure how they were positioned. mine I face the stern and they are in separate doors on each side . Picture just seems weird to me to be facing forward at the transom

They are shutoff valves in the center position. It says OFF right on the red sticker...
FYI, If you shut them off when changing filters, the fuel doesn't run back to the tanks. Easier to prime.

 

[Finest Kind]

As promised pictures below of the fuel valves and fuel Seperators. The valve on the left is for the Aux tank and the valve on the right is for the Main tank. Would you agree that the position of the valves below is only going to get gas from the Aux tank?

Yes, your pic shows the fuel valves are set to draw gas only from the aux tank for both motors.

So, are you saying that your issue is when you have your motors running from the aux as in your pic, and you turn both those valves to the main tank the motors die and wont restart?

If so, to troubleshoot it I'd do these steps in order going from simple fix to some work involved:
1) Remove the cap on the main tank fuel fill and try again...if still no good:

2) Remove a gallon of gas from the main fuel fill and try again...if still no good:

3) Snake a wire through the air vent tube to ensure its not blocked. you can try to go in through the vent outlet on the hull, or you may have to lift the deck hatch, remove the hose from the tank bib and go in that way.

These first 3 steps isolate whether or not the problem is due to a venting issue...If still no good:

4) Turn both fuel valves off. swap the 2 fuel hoses on the bottom of each valve from the main feed to the aux feed nipples. (be careful and try not to spill gas) Turn valves back to "main" and try again.

If the problem persists when the valves are on the MAIN position (but actually drawing fuel from AUX lines), then you have a bad set of fuel valves.
Replacing them is a bear, and you WILL skin knuckles and curse a lot...

If the problem is gone when the valves are on "main" (but because you swapped lines you are actually drawing fuel from the aux lines), and the issue "moved" to when the valves are in the AUX position (but actually drawing from the MAIN tank lines) then you know the valves are fine and you have a blockage in the main fuel tank pick up tubes, or in the main tank fuel lines from the tank to the valves.

Replace fuel lines to their original correct positions when testing complete.

The previous tests eliminated venting and the tank selector valves as the potential cause, if the issue persists I would continue with these steps:
5) Lift the hatch over your main tank and remove the fuel pick up tubes. Clean and reinstall. (you might be able to do this through the 6" round deck covers over the tank without having to remove the entire deck hatch)....if still no good

6) Replace the fuel hoses from the main tank to the fuel valves.

Go step by step and you will figure it out. You know for sure that from your filters back to your motors everything is fine, otherwise they wouldn't run from the aux like they do now.

Please let us know how you make out....

 

[Finest Kind]

See above, its either a venting/air lock issue, bad fuel selector valves, or clogged gas pick ups/fuel lines.
VERY curious to see how the OP makes out....

I had a similar issue a couple years ago, was getting a "code 137" (insufficient fuel) on my new Evinrude G2's which the dealer was insisting was due to a "boat fuel delivery issue".

In order to eliminate the boat as being the cause, I removed the deck plates, removed cleaned and replaced the pick up tubes, replaced all the fuel lines, replaced the fuel selector valves, and installed new stainless steel racor fuel filter holders and filters.

After all that work and expense, it turns out he was wrong and the boat system was fine, it was a bad VST in the motor which was replaced under warranty!

 

[Hookup1]

Good advise! I will reply back once I fix the issue.

Sure would be nice to know what's going on.