Reserve fuel tank is over full

[gmcop1]

On my 1984 43MY the reserve tank keeps getting over full when I haven’t added fuel. The only thing I can think of is that fuel is somehow bleeding down from the main tank. Maybe leaking by the the fuel selector ball valves? Anything else possible? I think this may be causing a diesel smell in the aft cabin.

 

[bigbill]

check the return valve and make sure it is working properly

 

[SEVEN]

You have both motors returning fuel to one tank.

 

[gmcop1]

The problem happens when the motors are not running. I reduce the amount in the reserve tank by running the engines from it and returning to the main tank.

 

[SKYCHENEY]

Wanna sell that boat? I've always dreamed of having a boat that made its own fuel.

 

[rustybucket]

Any chance it's water getting in instead of fuel? Water would displace the fuel up. I'd probably try to suck some fuel off the bottom of the tank and see what it looked like.

 

[gmcop1]

Not water, it happens too quickly.

 

[Freeebird]

Seems to me that the reserve tank has to be gravity fed by a main tank if this is happening while the boat is sitting still with the engines not running. That would be pretty dumb to have plumbed it that way. Is this supposed to be a factory installed reserve tank?

That may just be your terminology.

 

[rustybucket]

I'd lean toward a bad valve. I would disconnect the forward tank from the valve manifold and see which valve(s) was leaking, that should give you a very quick answer.

You could disconnect the hose at the valve manifold or at the tank, whichever is easier to access. Either will give you your answer relatively quickly.