Just got back from canada walleye fishing and had boat trouble and was looking for some ideas. Have a 150 mercury verado 4 stroke engine and the crank case filled what I thought was fuel. Brought it to mechanic and he said it was normal for a 4 stroke to as he called it make oil if idleing alot. So Knowing that we idled enough to fill the crank case.This is a first for me to hear of this. Any thoughts or ideas. Now as for the fishing 10 of us when and stayed on a house boat and tocaught aproximently 700 walleye a day never seen it that good been for 20 years.