Mercury 4-Stroke 50 HP EFI fuel pump problems

I have owned this motor for about seven years only use it for crappie and ducks. I began to have a problem with fuel pressure last summer and now have had 4 new fuel pumps installed @ a dealer. Mercury KNOWS they have a problem with these motors they have re-designed the fuel pump several times but can't seem to correct the problem. Does anyone have any similar experience? The motor runs great as long as you pump the bulb when it starts cutting down for lack of fuel. This is not a tank or line issue it is the fuel lift pump.

I have the same problem with my 50hp efi mercury mtr. This mtr. Has 2 fuel pumps & per the dealer fixing mine mtr.it is the mechanical pump that feeds to the electrical pump.at any rate i will find out in a few days.i think it is the ethylnol eating up parts in the pumps.

Guys do my a favor and change the plugs, and see if that helps you out. Its a cheap troublr shoot. You may be suprised with the results.

The old material used in the lift pump diaphram can not stand up to the new blends of gas with up to 15% ethenol in the gas. I have been telling all our customers to use Stabil or any other type of fuel treatment made for use with ethenol. The achohol in the gas affects all types of rubber parts in motors, and I have seen quite a off brand fuel lines actually come apart and plug up the lines and filters with peices of the fuel line. Treat the gas every time you fill up not just during storage.Tom