I would like to know if anyone has any knowledge about the maximum hours on a straight inboard engine before thinking about replacement? I understand a lot would depend on the proper maintenance done on the engine before reaching those hours. Let's say a boat that was really taken care of has around 4000 engine hours. Would we be looking at possibly needing an engine replacement soon? I know this might be hard to predict, but I'm sure some of the experts on this forum could venture a good opinion based on their experience. Thanks for any knowledgeable replies.