water pressure on 225 vmax

[duckhuntmcnutt]

i have a 225 VMAX on my stratos and i'm getting about 9 psi water pressure when running on plane.  i have always heard 13 psi is where you want to be and thats where my dads skeeter runs at also.  I have tried to trim down a little and put more engine in the water to get more suction but my guage still reads around 9 psi.  When i am trimmed way out and pushing 70mph right before the boat starts to chine walk i am around 5 psi.  Should i drop the motor down a little with the jack plate?  The guy who had the boat before me had a factory certifed mechanic set the jack plate for him and it was at "optimal height for performance and proper engine functioning."  I have a steady stream of water coming out the pee hole.  anyone got any advice?