Jun 30, 2012 #one There are plenty of water-in-the-oil threads so I just considered I would toss this on the market. Any water usually means a seal is leaking, and it may be as simple as an oil fill plug seal or as hard to be a prop shaft seal. https://jaredimops.robhasawiki.com/11329807/an_unbiased_view_of_mercury_outboards_electric