I have a 28' Checkmate with 29" labbed Mirage Plus props. In the search for more speed I am considering going to a 4 or 5 blade prop. Currently the boat runs 80 MPH on GPS at @ 4900 RPM with a lite load. Full of fuel and people the boat runs 77 MPH at @ 4700 RPM. The engines are stock 502 MPIs which have the rev limiter set at 4900 RPM but I do not think the limiter is currenly being touched with these props. I would like to know what pitch would give a similar engine RPM with 4 blade non labbed Bravo 1s or non labbed Hydromotive 4 or 5 blade props. Thanks.

The 502 needs to run at 5000 RPM so your pretty good there. Your labbed 29P runs similar to that of a 27P stock in a 3B configuration. So in a 4B you would need a 26P and a 25P in a 5B. But the deciding factor will be your drive heigth as to whether you can run 4B and 5B props successfully. The deeper your prop shaft the lesser the blades.

Julie