The peak horsepower rating of the SuperTigre G-90 is about 3/4 Hp more than the G-61. The main advantage, though, is that the .90 will swing larger propellers. We'll run a 12 x 8 to 13 x 7 prop on it. The .61 likes to run 11 x 7 or 8, or 12 x 6 or 7.