I have a 2006 Bayliner with 4.3L fuel injected engine. Just purchased it this year and ran it about 6 or so time with no concerns. On last outing I added 25 L of fuel on top of about 50 L of fuel. After letting the boat warm up and driving at low speed for a while I opened it up and the engine "popped" a few times than I backed off on the throttle. When I would hit it wide open it would pop a few times, kind of sounding like something smacking on the bottom of the boat. I also noticed once that it kind of hesitated when I punched it. Not sure if I had some bad fuel or what was causing it but it quit after a bit. Than at the end of the day when we were heading to load up I punched it wide open and my buzzer would beep, I let off and it was OK but when I punched it, it would beep. Not sure what was going on. Ideas?