500 EFI fuel pump oil?
 

Ok, I read in my factory manual that upon doing routine maintenance to check the fluid in the fuel pump/sea pump assembly, after changing the engine oil, I checked it ( little screw on side of housing), there seems to be oil/fuel in both and over full. Obviously I need to replace both mechanical fuel pumps, but I have had no issues with drivability. Anyone have issues or know about this?

That is pretty normal to have some fuel seep into the lube, especially if it hasn't been changed for several years.
Just drain and change the lube. Use Merc HP drive lube.

Ditto. All fuel pump diaphragms leak small amounts of fuel. That is why the oil needs to be changed yearly.

I'd check fluid level shortly after you replaced the fluid to assure your diaphragms aren't bad. The Mercury diaphragms don't hold up well to ethanol fuel and unfortunately fail prematurely. Be sure to check replacement fuel pumps as well as I've had to return 2 or 3 due to immediate leakage! The bad diaphragms can result in vapor lock in the 500 EFI also.

Yep.

Thanks for the info ! I will change it out and monitor it.

Do all 500efis have this setup. I was not aware of this.

Yes, 500 and 525 EFI. Always change the lube when changing oil, it only takes a few minutes with a mity-vac. As a matter of course I change impeller, impeller housing, and change oil in pump when doing an oil change.

Some of the very first 500efi's 99-00 didn't have them.

Curious how often you change your oil.

Most I let it go is 25 hrs, a full season for us. If doing more hrs. I'll change mid-season. Same goes for the drives.

Didn't know the early 500 EFI was set-up like that, good to know for reference. Good catch.

I will have to look tomorrow when I get to my boat.

Actually, the earlier 500 efi's don't have this mechanical fuel pump which includes those in my 2000 Formula. My setup has worked fine as I've experienced no vapor locking problems. This is likely due to my boating area not being as hot as inland lake boating.

I looked at my motors over the weekend and I do not have that kind of pumps.

Is there a big difference between the two ways?

Ok, do you have to pull the fuel pump off to change the oil? I have a vac, but can't get anything in the hole to suck it out. Can't believe there's no drain hole.

Ok, made me a little tube out of a chunk of steel brake line. Just wondering how y'all do it.

You can only get about half the lube out with suction through the fill hole.

I pull the whole assembly off every fall during winterizing and it gets a new impeller and new oil. There is always some gas in the oil.

Yea, I changed the impellers, then noticed it. I will definitely pull them all the way next time. You got to be a contortionist to work on the starboard side anyway, just pull em and just go through them.