How often do you guys change your oil? I put about 60 hours on the boat so far this season... 35 of which were in the last two weeks (I don't even wanna think about that gas bill!). Last year I put around that all season and the year before I got the boat in September so hardly put any hours on it. This year it looks like I'll be putting well over 100 hours on it if I keep up this usage. I see some guys change every 50 hrs, some 75, some 100, some just once a season. Oil still looks clean, but thinking I should change it with this much use.