Friend has a 2018 Pioneer 700-4 that sounds like the top end of the engine went out. He'll sell it to me at what appears to be a good price. Is it worth tearing into for a fix or better off looking for another engine? Haven't had a chance to look into it so I'm not sure exactly what went wrong. Has this been a problem with Pioneers? Anyone's thoughts on what it could be? Crankshaft?