Some have said the B model fuel system schematic looks like a 3 year old had a seizure with a pen in his hand.[/quote]
I think that all the Cessna 300 and 400 series twins with tip tanks (mains) had the same unnecessarily complex fuel system. The problem was that the fuel system returned unused fuel from the injectors to the main (tip) tanks. If you did not burn enough from the tips before starting to burn from the aux (wing) tanks, the excess fuel would vent overboard when the tip got full. I can't remember if the optional nacelle tanks (one or two depending on the buyer) fed an engine directly or had to be transferred to another tank first.
Joe