Tuna Man, I have a 1998 sailfish with f225 4strokes, I messed around with 19", and 17" 3 blade yammie props, I also tried the 4 blade 17" merc rev 4 props in which i stayed with. i like the bite of the 4 blade props especially runnin in the ocean, The props do not cavitate like the 3 bladers do...