Mercury outboard fuel problems

[cowboy8]

Hello, I have a 60hp four stroke Mercury. Recently on my way back to the dock at full cruising speed the motor began to stall. I slowed to half speed and it did fine for a few minutes until it stalled again eventually stalling completely and dying and not restarting. I squeezed the primer bulb and it ran perfectly for a couple minutes until it stalled again so I had to periodically squeeze the bulb to get it back to the dock. This seems like a fuel pump problem but it seems the injectors require pressure to operate properly. Any thoughts or ideas would be greatly appreciated.

 

[ONERCBOATER!]

I'm not familiar with that particular engine... but does that engine have a low pressure (lift) pump to get fuel to a high pressure injector feed pump? Sometimes the low pressure (lift) pump failing will burn out a high pressure one due to starvation.
Did you check filters? Water separators?

Sean

 

[cowboy8]

After researching I have discovered I do have a mechanical lift pump that supplies a reservoir that houses the electrical high pressure pump. All my symptoms seem to point there so testing the pump is next. I assume attach a hose to it and crank the starter and check for flow?

 

[Chris1956]

Check out the price of the rebuild kit for that lift pump. Often they are real cheap.

 

[ONERCBOATER!]

Lift pumps are often like carburetor pressure levels...4-7... maybe 10psi or 15psi.... they move volume of fuel and make sure it is available for the high pressure pump. Sometimes they fail and the high pressure one starves and you just get symptoms... Sometimes they take out the high pressure pump too.
Your factory service manual should have test procedures and specs...
But the stick a hose on it works pretty well... as does the temporary installation of a little electric diaphragm one they sell at auto parts store... just to see if it fixes the issue ad a trouble shooting option.

Sean