May be a little long. I have a 2019 x21 with 250sho, 2 10ft talons. Started with a manual jack plate top speed with just me was 67 but it porpoise some. added a hy jp to see if I could fix it. Speed seemed to drop no matter how high are low I ran the jp top speed seemed to be 61-62 at best. Was told to try a tempest 26 prop. Luck would have it I found a good used one. Started out running at 3 1/2 in ptp ran 61 went higher with jp slowed down to 59. Started back down with jp got to about 3 1/2 in ptp. Speed went to 61-62 went lower 62-63 went to the bottom of jp which is about 5-51/2 in ptp got to 64.
I thought the higher you went with the jp (to a point) the more speed you would see. not the case with this boat. I have not heard of running the boat motor this low. any thoughts. What am I doing wrong?