I would but after three days with the generator running on the port tank (24/7) we had to fuel up even though the starboard tank was still over half full. I need to get it sorted out for the long trips planned.
Could be a small leak in the port fuel line somewhere that introduced air into the lines. I have not had that issue on my boat.
1. The Onan MDBKN Generator has a lift pump but can it maintain net pump suction pressure on such a long line?? Good question. On the other side of the equation the injection pump is quite robust and delivers quite a lot of fuel back to the tank and when the fuel tank is full the filter and generator's fuel system is lower than the tank level so there should always be fuel there due to the syphon effect.
Most diesel engines circulate fuel from and back to the fuel tank. The fuel is a coolant and lubricant. Plus for gear-rotor positive displacement injection pumps the fuel cannot be "deadheaded". On our generators which are mechanical injection the fuel cools the injectors then the excess that is not injected into the cylinders is returned to the tank.. On the QSM11's the fuel not only cools the injectors but also the engine control computer then routed to a fuel cooler and back to the tank.
That was my thinking also but that wouldn't introduce air into the system and draw down the fuel level in the racor filter right? I'll inspect all of the lines and if any question replace. I also thought maybe a hose end fitting was liking air - but I got the thing running great on the starboard tank until I ran the boat...
The idea of separate feed and return valves on the generator fuel circuit is exactly that - so you can transfer fuel between fuel tanks. Our generators move a lot of fuel. There are no valves for the main engines other than the tank engine feed isolation valves and valves on the racor filters. You cannot transfer fuel using the main engines on our 500DB's. Consequently, the generator fuel circuit is used to transfer. So, in order to transfer fuel from the starboard tank to the port tank the generator would have to reliability run off the starboard tank which in my case it does not.
The dip/siphon tube in the starboard fuel tank is right under that cabinet and to pull it out first the cabinet needs to be removed then a hole cut in the floor into the engine room. There is only about 5 or 6 inches above the tank so I can't see any way to pull the tube out other than through the floor.
Holy f@%k...that sounds like a nightmare. I took mine out years ago to run the pyrometers from the ER to the bridge. But I just slid it to the side without disconnecting the myriad of shit in there.
