Out yesterday and saw after about 15 min. of running up and down speeds took toward highest and at 47 mph (graph gps) the tach showed 6500rpm. Immediately slowed speed way down as didn't like the over rev. Anyway to bring rpm's down a little - not sure what that would do to speed? Prop is 23 pitch Tempest+. Manual jack inner plate up about 1/2" from outer. Will moving up or down maybe 1/4" at a time increase or lower rpm's? Thanks for any help.