I recently went to launch my boat with a 1998 Mercury 115 2 stroke and it started fine but would die after about 10 seconds of idle. I could hear that it was clearly misfiring so I checked compression and spark today and the compression on all four cylinders is within 5 psi of 120 and the spark cleared 7/16" on a spark tester. This makes me believe it is fuel related but I don't know exactly where to start and any suggestions would be greatly appreciated. I also puled the carbs before launching and cleaned them so I am wondering if there is a vacuum leak somewhere in the fuel system.
