I found a 36' boat that I am really intersted in. It has a volvo penta diesel. I've been around inboards and outboards but never an I/O. I'm not sure on any model numbers and won't be able to look at the boat for two weeks. So what are some common problems or other things I need to check for on the drive? I dont want to buy this boat and then end up having to tack on the $$$$ for a new outdrive right after. Thanks