1999 Evinrude 4 stroke 70 HP exhaust causes fuel slick on the water
I have a 1999 Evinrude 4 stroke 70 HP outboard that starts and runs well, except that I have begun noticing when I start it and let it warm up there is a fair amount of pollution (I think gas rather than oil) that forms on the water surface behind the engine. The motor may smoke a small amount just after starting but does not persist. When I run it a full speed for a while and then let it idle I don't see as much slick, although in the middle of the lake it's harder to see. When I put the boat back in the dock, shut it off and start it again after a few minutes, the slick reappears. The engine has about 125 hrs since I bought it in 1999. I would appreciate any thoughts so that I can eliminate this problem and not pollute the water.