So I just picked up a Targa that is powered by a 90HP Mercury Optimax. I want to change the lower gear oil before running her this year. Ive changed the lower end grease in my 87 merc outboard and my 06 4 stroke every year for years with no trouble. But on this motor I noticed that the top plug that I always take out on the optimax has two plugs that are the same height on the lower end, but a couple inches apart. Before I started tampering, I was wondering if I could find out which one of these is the correct one..any help??
Thanks!
Thanks!