I have a 2019 20SLV Yamaha F90. Current Prop is a 13 1/2 X 12-K that came stock. Interested to see what others are doing with prop selection. First time out only get 23 mph with 3 people on boat on perfect water. RPM are about 5700-5800. Seems others are getting better speeds then that. I had 5 people on it this weekend and barely got 20 mph. If I go with stainless should keep same size or change. Would 4 blades do anything. Anyone else with same setup getting better speeds? Thanks for help.