Can anyone tell me how sound these engines are? I'm thinking of buying a Grady that has a pair of these on the back. According to the boat yard, the boat and engines have been well taken care of. I've seen them and they are very clean. They have 625 hrs. on them, I'm wondering when I can anticipate having to rebuild them, etc... What in the way of compression should I be looking for out of the cylinders? Info. like this and any other suggestions would be helpful when I demo them. I really appreciate the help.<br /><br />Thanks,<br />pfistey1