Mercury seawater/fuel pump
 

Last weekend i blew a oil seal out of the raw water pump and learned it has a cam for the fuel pump running in a gear oil reservoir. It made quite a mess from only 4 ozs. of oil and it tore the cam up from running it dry. I put a new water and fuel pump on today and decided to check the oil in the reservoir on the other motor and it was full of gas. So i put a new fuel pump on the other motor and hope the gas hasn't hurt the cam. What a chit rig for Mercury to design. These are 07 motors with 54 hrs. I know of several people here local who have had problems with the fuel getting in the oil. I guess electric fuel pumps and a blockoff plate on the water pump would fix it. If you have motors with this rig you need to check the oil in them. Has anyone else had problems with this ?

Same issue with the 500EFI setup too.

Warranty covered it didn't it Mark?

I had same problem but didn't leak as bad as yours.

Yup, I have worn the arm on 2 of mine. I now change the oil in mine every 50 hours (every other oil change) , seems like cheap insurance for me

Warranty covered the parts but not my labor and cleaning up the mess in my imaculate engine box :angry-smiley-044:

Same problem with my 575.
I change my oil every 25 hours and use Red Line Shockproof 75W90. It still has gas in it, and sometimes water too just to makle things more fun.
Some people I know don't ever change their's and never seem to have problems.........go figure?
Regards,
Steve

Same, routine checking on it during oil changes.

When I was at the Mercury factory earlier this summer I pointed it out to them. They were all ears.

Had the same issue with an older Formula and it actually cost me a motor due to fuel starvation. Expensive fix for a poor design.

I have gone thru 3 pumps so far. The fuel gets into the oil and then eats the seals out of the pump. Oil/gas mixture leaks past the seals and drips into the bilge. So now I have 2 sets of pumps and rotate them. While one set gets rebuilt, I use the other set until I see a leak. Then rotate them out - rebuilds in.

Pain in the azz. I did get rid of the stock Merc fuel pump and installed a billet pump from Keith Eikert. That set up does not leak as much gas as the Merc set up.

Did Merc NOT know about this problem???