Fuel from aft tank to main engines
My Pacific Seacraft 38T trawler has three fuel tanks: one to port that holds 175 gallons, one to starboard that holds 145 gallons and an optional aft tank under the aft berth that holds 90 gallons. The boat has three diesel engines: twin Cat 3126s located amidships close to the main side fuel tanks and a Northern Lights generator located aft, aft of but close to the aft tank. I have a manual fuel control system (levers) that allows me to control which tanks fuel is drawn from and which tanks it is returned to. The issue: I can run the generator (located aft) with fuel supplied only from the aft tank, which tells me that the fuel, while old, is still good and that the supply line from that tank is not clogged. I can also run the generator with fuel supplied from all three tanks (although I have no idea which tank it is actually drawing from). However, I cannot start either of the main engines with fuel supplied from only the aft tank. If I start the mains with fuel supplied from all three tanks, then close the supply from the port and starboard tanks, the engines run for awhile (I assume from the fuel in the lines) before they begin to cough, until I open the supply from the main tanks. What do I have to do to get fuel from the aft tank to supply the main engines? Is there a fuel pump of some kind somewhere in the line running forward from the aft tank that I have not located (I've looked)? Or do I just live with running the generator off the aft tank, and use up those 90 gallons that way (may take awhile). I am taking the boat from Chicago to Florida starting next month, and with Hoppie's on the Mississippi not pumping fuel for the foreseeable future (maybe never again), I would like to know I have those 90 gallons in my back pocket if needed for that long stretch between Alton and Paducah.