merc fuel pump

[fmc1942]

My 99 125 is not getting enough fuel, will run for about a mile and then seems to run on 2 cyl, can hit the choke and will speed up for a few seconds....have checked the fuel pickup tube and checked the fuel filter and replaced the squeeze fuel bulb, not sure but it may be the fuel pump is there any way to check it? There is a fuel line in and out and also another tube that goes to the carb intake...
Mac

[samari]

A good test is to take a vacuum and pressure gauge. Put it inline in the fuel inlet hose with a tee fitting run the boat with the gauge it shouldn't have more than 2.5" of vacuum. This tests for a restriction in the fuel system.
If it reads good clamp the hose and it should read over 4.5" of vacuum. This tests the pump itself.

[fmc1942]

does the vac. gauge need to be installed between the fuel tank and fuel pump or after fuel pump..
thanks
mac

[samari]

Before the pump.