I have a 1970 115HP Evinrude. It was starting and running fine until last week. When I went to start the motor, the wheel on the starter would engage the fly wheel, however it would turn very slowly or not at all. I tried it several times with no change. I figured it was not getting enough power from the battery, so I check it. The battery was reading on the week side, I charged it however it still read week. Therefore I got a new battery for it. With the new battery there was no change, but i didnt notice that the battery wires were very hot after a few attempts to start it. Any idea what the problem is or what I should check next?