I should have mentioned this too guys. As you know, it's nearly impossible to get all the old oil/gas/water out of the small reservoir when changing it. Last time mine was off, my mechanic (who agrees this is a ****ty design) drilled and tapped a drain in the bottom half of the housing, making changing the oil a LOT easier. You can see it in the 1st picture.
Bill, I switched to the Eickert pump too (more for flow/performance), and you're right, it doesn't seem to leak as bad as the stock unit.
Steve

What Merc motor is this?

Rage,
We have had this problem on the 500EFI and 575SCi Blue motors. I think it's going to be a problem on any Mercury with the one piece seawater/fuel mechanical pump. Some people never change their's until it craps out, because they don't know it's there.
I have just made it part of my regular 25HR service routine. I've been using Red Line in my supercharger, and since it's the best synthetic I've found, also in an application where gas contamination is a problem, I've been using it in the mechanical fuel pump too. I've also used Royal Purple 75W90 Max Gear. It's good stuff too.
Steve

525s with 54 hrs. Mercury does say to change the oil and inspect for fuel every 25 hrs. or 30 days whichever occurs first. The only way to get all the oil out is to remove the fuel pump. What a lame rig on a motor that cost this much. Zuckerman i like your drain rig. A West System epoxy syringe works great for putting the oil back in.

I've had my 502 mpi for about a year now and have not looked at this oil. Does anyone have some close up pictures of which plugs or fills to use, or procedures of how to get the oil out and how much to put back in?

Ryan

OMG, they have to know. I personally know of about 10 that have failed.
Just add it to Mercs other fine designs like Bravo uppers, gimbal rings, and couplers.

Look behind the seawater pump pulley on the right side of the housing in my first picture above (click on to enlarge). You'll see 2 screws. Yours will only have the top screw. You'll need a flexible piece of plastic hose and a syringe to suck the old oil out. It isn't easy. Another one of Mercury's great ideas. You would think they would have at least installed a drain screw like mine to make life a little easier.
Steve

HEY MARK, YOU SHOULD OF HAD ME DO THE JOB....

STAN

One of many reasons I shelved my Gen 5 motors inlew of Gen 4 with real fuel pumps and sep sea pumps...I hate those things.
Sorry you guys are having all this trouble.

I had those on my 525SC's...Had one go bad and rebuilt both, ran fine till I sold those motors.
Although, I agree with Zoom...