I was running a 24 Tempest with a manual jackplate set to 3.5" PTP and was getting 63-64mph at 5750 rpm. I unfortunately dinged my prop up a bit so I sent it to a reputable prop shop that repaired and balanced the prop for me. When I got it back I was only getting 56mph and my rpms dropped a bit. I asked him about it and he said to bring it back which I did and I am now getting 57mph. I still have a loss of speed and I'm thinking it might be that the prop wasn't correct out of the box as I have heard that before.
Another thing I noticed is I have lots of bow lift but still find myself at max trim to get max speed where as before I could over trim and start to loose speed. Will raising my motor 1/4" help?