I have a 90hp merc s/n 1b777319 exlpto outboard one a tracker v17 (2010). I beat up the original prop and decided to upgrade to a solas stainless prop in the exact dimensions. 13 x 19. When I got in the water with the new prop the hole shot greatly improved but the rpms seemed to go up and top speed went down. My question is I have the opportunity to try a merc quicksilver 13.75 x 21 stainless Prop and wanted to know if the diameter would make a difference. I’m a beginner when it comes to props. Thanks in advance for any assistance.