starving for fuel

[kmarine]

my neighbor has a searay 40 express 1994 with bluewater mercruiser 454 mechanical fuel pumps mounted to seawater pumps. the starboard engine will only draw fuel after the water separating filter is filled with fuel and primed. The fuel pump and filters have been replaced. If the engine sits overnight it looses prime. The fuel lines have been manually bled to check for obstruction and move freely there is not a antisiphon valve. This happens both on the port or starboard tank. Three mechanics are currently scratching their heads. considering a fuel system vacuum leak down test to see if it is sucking air in somewhere. Thanks for your support

 

[NHGuy]

Re: starving for fuel

It's just gravity. Put in a big check valve, or a fuel shutoff. It does the same thing an oil filter antidrainback valve would. An antisiphon valve only keeps the tank from self emptying.