mirage plus propellor

[osprey]

Hi Folks

First post.. I bought a 23.3 center console and I am going to do a refit this summer, so I'll probably be asking more questions in the future. My boat has a 225 merc efi with a 15in x 19 pitch mirage plus prop. My problem is that it seems that I can't get more than 4800rpms wot. A dealer in the keys told me that I should run a 14in x 17 or 19. Anyone running a 225 with this set up. I might be selling this prop if anyone is interested. Just had it refurbished and balanced. retails for 550+