I'm wondering what level of decrease in WOT rpm would constitute my motors being over-propped. Got a pair of Yamaha 250's (replacing last years225's) on a 25' BW Temptation. Yami specs say 4,500 - 5,500 rpm range. I'm swinging a 23 pitch prop (up from a 21 pitch on the 225's) but have not had it in the water yet. 21 pitch produced just about 5,400 rpm. With 25 more hp, and the engines set up a notch on the transom, I'm hoping the 23 is the right prop, however if RPM's decrease, at what level would it be considered over-propped?