I grew up Skiing behind my grandpas 74 wriedt maverick and have always wanted to get one of my own. This past December I got a call from my uncle telling me that if I wanted the boat it was mine. I have been itching all winter to get it and out hear that 455 olds that I grew up with.  At idle it has a very rough rubbing or grinding sound in the bottom end . It smoothes out and responds right away when you give it a little throttle. Any suggestions would be great. I have some experience under a car but have never been involved in a rebuild. Any suggestions on where to start or what I might be looking at would be great.