was out yesterday everything great after anchoring and swimming started both engines, put both in forward and was puttering along away from swimming area, then decided to get up on plane. Immediately high rpms on starboard engine but no movement. Idled back down and tried again, then in reverse- same result: plenty of engine rpm, but no movement of starboard engine. During this time while trying in forward or reverse and whirling sound. No grinding or high pitch whining, but like a loud (well loud enough to hear over engines) whirling. Had to come back to dock on port engine only.
Inspected shift cables to engine- everything functioning visually. Of course boat is in water and I can't really see the ourselves even in up position due to swim platform.
Thought maybe i threw a prop or the hub, but does a 2003 mercruiser 5.0 MPI bravos have hubs in the props. They are dual props and counter rotating.
Didnt inspect behind engine inside where shaft comes out, but there was no biting rubber smell or anything like that.