Okay guys, gotta get in on this. I have a 2011 f115 doing everything that has been mentioned through out this posting. I took to a dealer, they replaced two of the four injectors. Boat ran fairly well all last summer. Parked it for the winter with 1/8 tank of gas, filled with sea foam and ran for two hours on the muffs. Was confident that fuel system was laid up for the winter. Filled tank to the top and added 1/2 bottle of sea foam.
This spring I pull the boat out, idled for two hours and sounded like a champ. Ran on lake for 2 hours then lost all power after 4500 rpms. When I ease up to full speed it'll start to miss. I can trim the motor up and get a bit more but never over 4800 rpms. I put all new filters in, all new injectors, pumped fuel into work truck out of the on board tank. I then added a fresh 5 gallons of gas. Darn thing is still doing the same thing. Took to dealer, found gas in oil, change #4 injector as it was stuck open. They drained the VST, which I can not figure out how they did it.
So short of changing the ECU and the coils I'm at a loss. Oh, forgot to mention that I also changed the fuel bulb incase that was the issue.
I could sure use some help with this.