That is what i used,10w 30 quicksilver,i know it's just good old plain mineral oil with mercs additives added to it.I know this would be a whole dif thread sometime but it makes no sense whether a outboard is broke in with synthetic or mineral oil,oil is oil,yes i know the whole theory is the synthetic is to slippery but you watch and see in the next say 5-10yrs that will all change.
This is almost like when all manufactures said never use synthetic in an outboard ever and that was the case a while back,now some manufactures want you to do it after break in.In time it will all be synthetic for break in.It doesn't really matter whether you use synthetic or mineral oil in an outboard anyway as it will do the job but i do know the synthetic does protect a bit better.The problem is from all i have read and heard is that synthetic oil keeps an outboard motor to cool so it doesn't reach full operating temp(mostly people who troll with them) and can cause condensation which in turn will look like your making oil as with reg oil it will burn a bit hotter.How true this is,who knows.I do know that most if not the majority of people after breaking in an outboard they go to synthetic.
But anyway thanks for the info.I just have never used mercs oil.I have heard good and bad things but mostly with their 2stroke oil,that it smokes like crazy compared to other tcw-3 oil,but this is 4stroke oil.