Yike, are you kidding! Mine doesn't do that. On most marine engines the
exhaust is expelled under water.

"tom clark" wrote in message
om...
On starting and after about 5 minutes idle my Merc 20 outboard has
thousands of tiny oil bubbles coming out of the exhaust below the
water line.
Is the mixture too rich? too much oil ?( 50:1), head gasket ?( runs
fine).
Thanks