I assume the 2004 boat in question is just nearing the end of its second season? If so, 80 hrs per season seems pretty normal and ordinary to me (I put on about 100 hrs per season in my boat and that involves about 60 days per season sailing).Another factor is how the engine hours were calculated. If the PO told you he recorded 160 hrs I would trust those numbers. If the numbers come from reading the hour meter on the panel, all bets are off as the hour meter may keep running when the engine is off and the ignition is on...meaning the actual engine hours are really lower.In any event, 160 hrs on a two yr old boat seems quite minimal to me. As others stated, the real key is what maintenance was done and how the engine was used. To me, this is a nearly new engine....