Hey everyone I have a 650sx and I'm in the market for a new prop I have two choices a 15.5 or a 9/17 was wondering what the performance difference is between these two props my ski is a light mod with a factory pipe and sbn 44 carb I'm 6'4 220 pounds Im looking for a low to mid range prop I'm not really looking to break records in top speed I'm happy Bering around 40mph any help would be great I'm a noob thanks