I might have found the culprit, in the FSM there is a vacuum hose (circled in red) that I read many posts saying that it would get a crack in it and since it is submersed in gas it would start sucking gas into the crankcase. When we unplugged the fuel line, the pump shut off and the vacuum shut...
I got a 2008 Pontoon from my ailing uncle. It has been sitting for several years. It has a 2007 Mercury 115 4 Stroke. We replaced the fuel lines, fuel, impellar and oil; that got her to start up but she wont idle. I can run her at around 1200 rpm but she runs rough and is smoking bad. I am...