Thanks for the suggestion. I will check the the oil like you suggest. float valve sounds like it may be the problem. I will reply when I have checked it out.
I also have a 2015 Mercury 20hp 4 stroke. It is carburated not fuel injected. I have a drip of fuel I believe is coming out of the exhaust tube ,but not sure. I could not feel fuel under the carb or around the inline fuel filter. The engine starts and runs OK. The leak seems to stop when I tilt...