Hi, to start out I am new to working on jet skis, but have had alot of experience with snowmobile engines and other smaller engines. I found a waverunner on a local classifides website and the guy said that it runs perfect, but last time he rode it he heard a noise in the jet area that sounded like a rock. My first thought is a bearing in the drive shaft, but correct me if I am wrong. Anyways, the guy only wants $550 bucks for it with a pretty decent yacht club trailer, I am more then likely going to buy it, but was just wondering if there are some things to look for when inspecting these for purchase. If it is a bearing going out in the back, I just want to fix it before the summer, so please give me some instruction on doing this or maybe a source for a diagram. Thanks, your help is greatly appreciated.