I know this board isn't big for this, but I do a lot of trolling for coldwater fish. My 1995 25 hp Mercury is making a bad noise, mostly while I am idling along just in gear which I obviously do a lot. It will be quiet for a while then it will start making a high pitch squealing noise that will come and go. Recently it seems to be there more than not. It doesn't make this squealing noise when it's under half throttle or more. It also doesn't seem to affect speeds or fuel economy. It sounds to me like it's a bearing of some sort, what kinds of bearings are replaceable in my motor? I know there is one in the lower unit, can I replace it myself? Could it be the water pump? Just trying to get some feedback and thoughts before I tear into it. No way I am bringing it to a dealer. I need to do a new water pump anyway, so I guess I'll start with that,