I have a new Ranger Comanche 518 L, 13 hours on the New Pro XS 200 Mercury, Just broke in by the book. The prop I am running now is a Fury 22P and I am doing good to get 52 MPH at 5200 RPM. This Motor RPM range is 5600 to 6200 and I can't even get close? One mechanic told me to take it back to Cabela's something wrong with the motor. Another mechanic told me to drop to the 17 or 18 pitch prop as I can gain 200 RPM for every inch of pitch decrease and this would put me where I need to be? The boat comes out of the hole very well and gets to speed fast but then that's it. 52 mph at 5200 RPM? Boat has manual Set back that measures 3 7/8 Pad to prop so the height is good. I just think the altitude here on the high plains of TX is the problem. I'm at around 3000 Ft. The Cabela's I bought the boat from is in Allen TX with much lower altitude and the boat would probably run great there or at Lake Fork. Mercury Prop Selector says to use Tempest Plus 19 or Fury Four 24, So any ideas before I spend another $700 or more on a prop? Thanks