I am running a Johnson 235 (85) on a 1998 Glastron 17' with a 19 pitch prop. When I'm pulling a skier and I have 2 others in the boat with me it does not pop the skier up right away probly takes 10-15 seconds to plane out. I am looking at buying a 15 or 17 pitch and am not sure which one to go with same thing on size. What is the difference between a 141/4" and 15"? Any help would be appriciated.