I have 2013 Z9 DC with a Merc 250. When I'm by myself and 1/4 tank I get great lift and run 68mph and turn 6600rpm. Add a person, any person, and I get no lift and run 59 mph at 5900-6000 rpm. I'm running a 25P Tempest+, I've run 24p and 25p Fury 3's with no better success. Any help is appreciated!!!