I have a yam 50hp 2 stroke with a four blade prop with a 12 pitch. It came with the boat and i have been running this prop since. It has a good hole shot, but my top end is around 25mph and 26mph on a good day according to gps . I do not have a tach to see rpms and not sure if this is the right prop or wrong prop. I understand a 3 blade will give better top end but losses quicker hole shot. I heard someone say i should be running a 3 blade prop on my tunnel since i do not have a jack plate. Any info or suggestion will be much appreciated.