The Max RPM range is 4400 - 4800. You need to compare the current performance against that target in order to determine how (IF) you can tune better.
Going down in pitch will increase max RPM and time to plane, but decrease top speed and cruise speed. However going too low (under-propping) can lead to potential over-revving.
Going up in pitch will decrease max RPM and time to plane but increase top and cruise speed. However going too high(over-propping) can lead to overloading the engine and in extreme cases, not being able to properly get on plane (especially when there is increased gear and people load).
So, we really need to know what the current Max RPM is at WOT. Get the boat up on plane, then trim out the drive until it cavitates, then click the drive back in until the cavitation stops. Hold it there for a few seconds and see where Max RPM is. It's best to do this in calm conditions with little chop or wake traffic.