Originally Posted by Oscarguitar
Your old prop might have been out of balance. I have had problems with a couple of props one of which was brand new. Also it could be that you are in the right "gear" now using the 17" prop so the engine is not lugging.
Finally, have you checked the height of the anti cav plate at cruise? If the engine is too low you could find that by raising it up a hole or two you could run the 19 and get a couple of hundred more rpms.
Thats my next task, im going to mount my drfit action video cam on the boarding ladder and film whats happening in terms of water flow at various speeds and trim for viewing and analysis later.