How does the generator work when first coming out of storage? It is drawing on the same tank/fuel? Seems weird that after you fillup it works fine for the rest of the trip. How low do you let it go before filling up again?
Unless someone is putting water in your tank while in storage? do you have a locking gas cap, get one.
There was a post some where about the potable water leaking down into the gas fill hole. They stated when they filled the potable water tank, due to the way the overflow line was run, it would siphon water out and run down the side into the gas tank fill area. (something like that, I believe)
It's just a thought???????