Last time I ran the boat was early Oct, boat ran great. I parked it and kept batteries charged, going out and cranking it once or so every 3 or 4 weeks. Went to do the same thing today and the passenger side motor appears to be locked up. The starter was making a straining noise without the motor rolling over so I didn't keep trying it. I pulled the plugs out and cannot rotate it by hand either. The other motor rotates easily with the plugs still in so I'm sure its locked. How and why though would this have happened? Any ideas would be greatly appreciated. Is this a simple top end rebuild....hopefully?