Can Anyone tell me what the best rating is for a Battery for the 1990 50HP Force? How many amps are sufficient enough to crank the engine. I just picked up this engine and I looks like my current battery is just not enough to crank it. Well, it cranks, just doesn't turn over. I know I need to tune it up, but it should at least start. just not enough Juice to spin the starter enough to get it to go. Any thoughts would be appreciated.