Fuel Pump maint. and RMP issue on 5.7 GXI-B

[owenscountry]

I Have 2 quesions: First does anybody know what the new maint. on the 5.7 GXI fuel pump is? I know they wanted me to run a mixture of 2 cycle and fuel into the pump before storing it to keeop everything lubrcated. Second, During the coarse of the year I couldn't get the boat over 3400 RPM's while it was in Gear. In neutral i can get it to red line. In the manual it showed that it should be operating between 4000-5000. The boat runs great no hesitation, no problems pulling anyone, etc. just can't get rpms up. Right now it has a 19 pitch 4 blade prop. Is that too much prop or do I have a bigger issue? Thanks for the help!

 

[Don S]

Re: Fuel Pump maint. and RMP issue on 5.7 GXI-B

That mixture is not for the fuel pump, it's how you fog the engine on an MPI engine. You can't fog them like a TBI or carbed engine because of the intake manifold design. So Volvo (and Mercruiser) use a mixture to get the fogging oil into the cylinders and valves before extended storage (Winterizing for many)

During the coarse of the year I couldn't get the boat over 3400 RPM's while it was in Gear. In neutral i can get it to red line.

In neutral, you could take half of the spark plugs out and get over 5000 rpm, that is a non test and means nothing.

Did the rpm drop when you installed that prop? If so, then you found your problem.