Mercruiser 4.3 prop

[Seapro21wa]

Hi guys I just picked up a SeaPro 21WA. It won’t go above 23mph at 3800rpm. I’m assuming it could be the prop as it runs great other than that. Does anyone know what is the correct prop for this application? I was thinking 14.5x17

Please Help!

 

[alldodge]

Don't know but what prop is on it now

 

[Sea Guardian]

You stated 23 MPH at 3800 on a merc 4.3. Can you get above 3800 or is that the top RPM you can pull from the engine? I have an 06 4.3 merc currently using an aluminum quicksilver 14.5" 19 pitch. Whole shot great, but i hit the rev limiter @5000 rpm.