Yanmar 3gmf fuel problem

I have a 3gmf engine in a Hunter 34. It has high hours, but the oil is changed every 50 hours and it has a Racor 10 micron fule filter and that has be changed several times. It has plenty of fuel in the tank and all the fuel lines have been changed. What happens is the engine will die , but after bleeding the system it will start back up and run for sometime. Here is the latest scenario: It sat for 30 days, but started right up and ran for 9 minutes. I bled the system, restarted and it ran for 40 minutes, bled the system again and it started and ran for about an hour and a half when I shut it off. Suggestions

You really have some air entering the system. Some line is leaking. You could install a piece of clear hose, just to look for the air in the fuel line.

Hi, are you filling the racor with fuel before bleeding the air ?? Fillit up bleed the engine and run at high idle for 20 minutes or until it stalls. Remove the top from the racor if the level of fuel has dropped in the filter more than an inch your air leak is between the racor and the tank, if the fuel level did not drop it is at the racor to the engine. Also what racor model are you using ?? Do you have brown stringy bacteria in the filter ??
Charlie w.

Make sure your tank vent is not clogged also. You can simply remove the fuel fill cap, run the engine and see if it still stalls or not. I have also seen several defective Racor filter element, so you can try changing it also.