A guy has a boat for sell. He says it is a 1989 200HP Black Max but the hood on it says 150. Claims a place he like to boat didn't allow 200HP's on the lake so he put the 150 cowl on it. Can't make out enough of the Serial #'s to verify. How do I know it is a 200 and if it is, how do I tell if it is a 2.4 or a 2.5?