Does anyone know the amount of gear lube it takes to fill the foot on a 200 hp Merc? The parts store sold me 3 qts @ $$$$ and I can't get any more than about 3/4 of a qt in it? I used a pump to put it in from the bottom and its running out the top vent. Thank You for the help.

I don't run a 200 Mercury, but my 150 holds just about what you put in it.

If you are filling from the bottom and have the motor trimed down level it's full when the fluid starts coming out the top hole.

Thanks so much. I used to have it done but can't afford $120.00 an hour for things I might be able to do myself well that is with help like yours. Thanks again!

X3.  Just make sure that there are no air bubbles coming out of the upper hole along with the oil.  When I re-lube my lower unit I fill it until oil starts coming out of the hole and then I stop and wait a few minutes to make sure all of the air has been evacuated.  Then I add more oil as needed.