Good Morning
what HP is your Yamaha
I have the following powertech 4 blade stainless steel prop - used as spare
POWERTECH SCD4R 17 P - YM90
PROP DIAMETER - 13
PITCH - 17
GEAR CASE - 4.25 "
I couldn't get near my maximum rpm on my 2019 Yamaha F 90 around 5300 rpm WTO
I'm running the same prop only with a 15" pitch & now can run 5900 rpm WOT
if you google kijiji ad
1506175206 there are more details
Thanks
Wayne