Thanks, Phester...but I'm not really a prop expert...I just read V-20.com ;)...
Jackman, 44 does sound low, but the 5500 is more of an indicator to me that it's prop'd wrong...my 150 tops out at 42 mph at 6000 rpms...
what's the Honda's max rpm rating on the 225?...to ''get it all'', that's what to shoot for and your top speed will result...
Try these guys;
http://www.ptprop.com/
They make props FOR Honda and they'll evaluate your set-up and tell ya what ya need ;) ...