Alright guys, this one has me stumped and I need some input. Carbed Gen Iv 454 with a Bravo 1 outdrive. I ran the boat friday to our river house and anchored out front. Boat ran perfect as usual. I stayed on the boat sunday night because we had a really bad storm come through. All is well. I go to start the boat Monday and it made a really strange thump sound when I hit the key. Nothing really happens and it sounds like the battery is low. I switch batteries and the same thing. I then pull from both batteries and it rolls a couple times and starts up. Now after sitting for a few days I have a knocking sound from the engine. I have tried to diagnose the problem but can not pinpoint the sound even with the stethascope. It doesn't have that deep rod or bearing knock more of a higher pitch(if that makes any sense). The engine will idle but won't take any throttle in gear. Running kinda crappy. I assumed maybe the fuel pump has frozen up and its not getting enough fuel. I pulled it and it seems to be free and moving properly. I pulled the starter to make sure it wasn't dragging the flywheel. I haven't pulled the valve covers yet to make sure it wasn't a broken rocker. Just wanted to see if anybody had any ideas or possible things to look at.
