I have a 2005 190 proV with an 05 Mercury 200 Optimax. This engine has about 250 hours and has been checked out totally by Don Weed and given a thumbs up. My engine runs great and has good compression.
When I bought the boat it had a 27 pitch Tempest plus and would run out to about 72 tops at 5200 RPM's. I played with the jack plate and the further up I went, the easier it was to drive, but the slower it got. At about 1.5 inches below pad I begin to blowout getting on plane and the top speed would be 67.
I switched to a 25 pitch OT4 4 blade prop and I get real similar results. It runs up to 5350 RPM's and tops out at about 70 MPH GPS. I realize how stories go, but I have talked to several people with a similar setup to mine and they are running 74 to 76 MPH.
Does anyone have any suggestions on what I could tweak to get my speed up? I have a 10 inch jack plate installed.