I have a 1995 force 40 hp outboard and ever since I bought my boat it's fired and started with no problem. But today was like any other I put in and rode up river then rode down river turning it on and off as I stopped and fished. But when I got to the boat landing I ran out of gas and the motor shut off I had some extra gas and poured just enough in to where I could load it up. When I went to crank the motor it acted like the battery was dead. But the volt meter was reading 12.8 and it's a brand new battery. I took the hood off and turned the key and the starter comes up fine but will only turn the flywheel one turn at a time really slow. Left it sitting for an hour came back and it started right up. Turned it off and tried to crank back up and the starter was lugging again. I don't know where to start any suggestion? All connection is seem fine and doesn't seem to be grounding anywhere