I have a 2010 Skeeter FX 20 with a 250 SHO motor currently running a FXP 26 pitch prop. The motor was rebuilt at 99 hours and currently has 162 hours. I purchased boat August last yr. At time it had V max 27 pitch prop and top end 74+ with RPM 5900. I switched props to improve hole shot and was running 71mph with 5900rpm. I was running on # 7 on hyd jack plate set on 7. Now for some reason I can't get above 5500 with either prop. Moved up jack plate to 9 still 5500. Moved to 11 still tops at 5500.Dealer thinks I have bad gasoline. I use premium nonethanol gas and use ringfree also have went to three different gas stations. changed 10 micron filter. Lost and flustered