Looking over the fuel line plumbing yesterday as my current plan is to only use the aft tanks until the forward tanks are cleaned. I was surprised that this mass of tubing did not alow me to pick what tanks to pull from but I'm good with it. What I don't understand is why all this complexity for return lines? Secondly, there is a valve in the middle that ties the return lines together. In my mind that should be closed, forcing the returned fuel to either port or starboard. On my boat it is open. Lastly, I didn't trace out the bypass line. Where does that go and for what purpose? When I tried getting info from my previous owner on this set up his comment was that he just never touched it.