Took my Rinker out for the first time this Sunday(what a glorious day). Its fitted with a 4.3ltr merc alpha 1. We noticed a bit of a sound at idol, a slight rumble. We took the main drive belt off which meant that the sound could only be either, the crank or gimbal.The engine looks clean,and its had a new flywheel and starter and exhaust. Could this possibly be a slightly worn gimbal bearing? Anyone ever had to replace one, what were the symptons? How big a job is it to replace? We dont need to remove engine do we? Rough cost for a marine engineer to do the work? Cheers guys Si