I have a 2006 225 PRO XS on a 19 ft PRO V. For the last 3 years I have run a 23P Tempest on it which ran 58 mph at 5400 rpm. I recently changed my lower unit and now the engine wants to run past 6000 rpm and can hardly hit 50 mph with the same prop. Both gear cases are torque masters and both ratios are 1.75/1. Any help would be greatly appreciated.