I've got a 15' Riverhawk (same as a Gheenoe, basically a skiff/canoe hybrid) rated for a 10hp engine. I have recently acquired 2 motors for it, both 2 strokes. One is a 2000 Yamaha 8hp and the other is a 1999 Nissan 9.8hp. Both are in excellent shape and in virtually equal condition. Since I...