fuel venting

Doug,
Im mystified on this one. I was running my westerbeke generator today and after about 30 minutes of operation diesel fuel started coming out of the fuel tank vent. any ideas?

thanks
bill
brewer 44 Aguila

Was the genset drawing fuel from one tank but returning it to a different tank?

that was my thought, but the fuel valves were all pointing to the same tank. Does not do it when the motor is running.

I think you are sucking fuel from one tank & returning it to another tank that is full thus it is coming out the vent. Fred Wild Oats

That is what I thought. However, both valves are pointing in the same direction. Is it possible that the genset only returns to one tank regardless of where the fuel tank valves are set?

First, it is possible that whoever installed the genset didn't route the return line through the tank selector valves so it always returns to the same tank, regardless of which tank it is drawing from or how the return valve is set. You could check this by either tracing the plumbing for the genset, or by running the genset off the tank that overflowed and see if the problem goes away. Also, if the level in the tank the genset is drawing from seems to go down too quickly for the amount of fuel you would expect the genset to burn, then the genset is probably returning its excess fuel to a different tank.

And finally - grabbing at straws - are you sure that when both the handles point the same way that both valves are really connected to the same tank?

Just a thought... Hope it helps.