I've been having my 2013 Yammy F70 (4 stroke) serviced by Rockwall Marine since it was new. I decided to do it myself this go-round. Got the oil, oil filter, fuel filter, water separator cartridge done. It's the off-year for the impeller, so I'm not messing with that this year.


Went to drain the lower unit lube, and noticed right away it is blue, so I stopped draining any more than the few drops that came out. The Yamaha gear lube I got is normal clear/brown in color. Will I run into a compatibility issue with the Yammy lube in place of whatever is in there?

Not saying anyone did anything wrong, just want to make sure what I have isn't going to create a problem when used with the residual amount of the blue lube that will be left behind?

Thanks,
Jay

Your fine. The blue lube is probably the Mercury High Performance Lube which is a synthetic blend I believe. Your going to drain out the old so there won't be enough left in it to harm anything.

That's what I figured, just wanted to make sure. I know certain bases have issues with others when it comes to grease, just wanted to verify this isn't going to be the case with these two gear oils.

Thanks

Agreed.
And yes, There can be compatibility issues.

You could let it drain overnight, or for a few days if you wanted to.

Or, you could swap the Yamaha lube and get the Mecury high performance lube.
It's what most of us down here use, regardless of outboard brand because it holds up better than anything else. I use it in my twin Yamaha's that we run offshore in 100 to 200 mile trips on a regular basis.

I bought two quarts of the Yamaha and it isn't worth the expense of returning the one I have left. I went ahead and changed it yesterday. Since I have plenty left, I guess I'll do another change soon, then decide which one gets put back in it next year and stick with that from there on out.