Ok, so I cleaned the valve, checked the filter, and checked the valve in both positions. flow is good on both positions, and no bleed over at all. I fixed a small leak in the connection to the e-pump, and tightened down all lines. ran the pump and checked for leaks, all good. I went to the fuel station and put fuel int he rear tank, "there was none before" I left the pos switch on rear and took off, about 50m down the road I came to a dead stop because the engine died, and would not restart till I switched it back to front and let it prime a bit. The e-pump runs off the ignition switch "at least the PO got that right" I noticed that there was fuel in all of the lines, coming from both tanks when servicing the selector valve, and it was clean too, no muck. clog in the rear tank? possible? is there a screen or something? ****** perhaps "I know that old trick" I would just sump it and call it a day, but the spare mounts there, I'm not looking forward to dropping the tank. any advice?