Re: 1993 Mercury 90hp impeller
It is a sign your water pump is working, but absolutely not reliable sign water is getting everywhere it should. I blew up a motor thinking that way, expensive lesson. Install a heat guage or better yet a water pressure guage in the top cylinder of your outboard.
What happened to me was a the water jackets clogged, restricting water to the top cylinder. $800 later, I had my 1980 Mercury 40 hp running again.:redface:
