Engine Starving for fuel

[dannywadd]

Engine is a 1997 mercruiser 5.7l 350 with a mechanical fuel pump. I have been chasing this problem with my boat all summer. Boat runs and idles real good for about 45 minutes or so then starts stalling out. When trying to start it back up it sounds like it's starving for fuel. After awhile of cranking it, pumping the throttle, and cranking it at WOT it eventually starts back up. It has stalled while I was just sitting there floating with the engine running, when I have gone to give it more gas at a cruising speed, and when I have been going through no wake zone. I have replaced the coil, all spark plugs, bought a refurbished 2 bbl carb, just recently had the anti-siphon valve changed out, and have changed out the fuel/water separator filter. I have also tried running with the gas. so off to see if my vent was plugged up and it ran a little longer than it was but still ended up shutting off after about an hour or so

 

[Bt Doctur]

try running on a remote tank , check coil for excessive heat,

 

[dannywadd]

try running on a remote tank , check coil for excessive heat,

the coil has recently been changed out

 

[Bt Doctur]

didnt ask if it was changed, asked about it heating up
then run a remote tank for testing , temporarily rig up a fuel pressure gauge to check fuel pump. You need a steady minimum of 6 psi.

 

[dannywadd]

didnt ask if it was changed, asked about it heating up
then run a remote tank for testing , temporarily rig up a fuel pressure gauge to check fuel pump. You need a steady minimum of 6 psi.

okay i’ll check the temp next time i run it. my mechanic said he ran it with fuel pressure gauge and it ran at 12 psi

 

[Bt Doctur]

12 psi on a carb and your flooding the motor. the needle and seat cant handel that much

 

[Bt Doctur]