Hoe serious is water in the lower unit? What can I do to fix this. And a approx. how much lower unit gear oil does it take to fill 1971 merc 135 HP. Thanks How do you to a vacume test on the lower unit.
I recently purchased a boat with a 1971 mercury 1350 outboard 135 hp. When I drain the lower unit oil, I found water. What could this be caused by? Also, where would I find the thermostats? Thanks for the help.
