Hello everyone! Looking for engine advise. My wife and just looked at a 2000 Mainship 390. We liked the boat but have one major concern. It has a single Yanmar 300hp engine with just about 6000 hours on it. Has all maintenance records and owner is replacing the timing belts this week and transmission oil. How many hours can we realistically get out of this engine if it is indeed in good shape? (will have mechanic look at it) If the engine is "overhauled" how much more life will get get out of it? How much (ballpark) is a replacement?