I bought a 2001 bass tracker 175 xt with the 50 hp 2 stroke Mercury on it, when I bought it, it had a Solas Amita 11"x15p aluminum prop on it. Motor runs good, but turns 46-4800rpm. So a guy I work with said he had tracker 165 with the 40 on it that was the same prop spline. So we decide to take his Apollo 993407 10 3/8"x14p stainless try on my boat. Worked flawless, rpm 5500, felt good taking off, turning and all. So I come home and order the same prop and hub kit he has. 993407 prop and 114 xhs hub kit. So we put my prop on and take it for test run. Same amount of fuel and gear, and my rpm will pull 5000, no higher at w.o.t. but with his prop we got 32 out of it and mine got 32.9. my question is, are these props pretty consistent from one to the other? I can't figure out why rpm dropped and speed went up with two of the same prop.