Re: 1996 XR6 150...Changing Lower Unit Oil
yeah check with a small screwdriver or a pick on the plug holes they often stick there - ask your parts guy if he carrys the newer nylon type gaskets .
just flush out the leg with by attaching the pump fitting to the top hole and pump 4 or 5 pumps through -then attach it to the bottom hole and fill as normal til it runs out the top then give it 1 or 2 more to get the air out .
you dont want to use any other type of oil in there unless your doing a total overhaul and clean it all out - the oils may not mix well and you dont want any foaming in there which would starve the gears for lube and create pressure that will rupture seals leaving you on the water with a trashed leg .
Use the merc gaskets. Get some spares, as they should be changed every time you pull the plugs.
I ( and Mercury) disagree with the procedure. You fill it from the bottom till it runs out the top, then let about an ounce drain out before you put the bottom plug in. That is to make sure there is an air space over the lube to allow for expansion.
Best fluid to run in that one is Merc High performance lube. If you think it needs cleaning, fill it with the right fluid, run it a bit, and drain it. That gets a bit expensive, but I think one round on yours might be worthwhile.
The silver paste could be coming from sloppy shifting. If you let it rattle into gear when you shift, you'll shed a little metal off the dog clutches. You should smartly shift it into gear with a single clunk. Believe it or not, that is the way it is supposed to be.
hope it helps
John