Pretty sure the fuel will equalize between tanks. It doesnt do it immediately (reason for two fill caps), but it seems like mine equalizes. I would take the hose off the tank to the selector and see if it is coming apart inside. Also, might not be a bad idea to check the hose from the selector to the outboard. If its a “lined” hose then it could be separating.JohnJones Trolling Motor Services870 773 3474Motorguide/MinnKota/PowerPole/Lowrance/Humminbird