bellabeitz
New member
I have a merc model 850 outboard motor, when I fired it up in a barrel of water for first time it left a dark oil spotty film and from what I could see it was coming from around the prop where it usually drained a little water from in the past but never noticed oil before, this looks like a water oil mix, not creamy or grey but darker, something to be concerned about? when I opened the oil plug on leg there was no oil or water draining but there was oil in it but maybe low, which brings in to question what is the best oil to use, I used ordinary motor oil last year 10-30. compression test 119-119-115-120? still good?