Prop Help - 1994 Grady-White Marlin 280/300

[GScott13]

HI Ken,

Hoping you might have some advice on the correct prop for me. I purchased a 1994 Grady White Marlin that I'll primarily be using for cruising and some fishing, but nothing that would require the boat to be significantly loaded down with gear, ice, etc. I am in the process of rigging twin Yamaha F250s (F250TXRD & LF250TXRD) that I actually procured through Andy Munao at SIM Yamaha.

The engines are coming with the 21P Yamaha Saltwater Series 1 props that were on them, and was hoping you might have some insights. The research that I have been able to do leads me to believe that 21 might be too much pitch. Based on what I believe my usage will be, I'm thinking fuel efficiency would be the top priority.

Any help you could provide would be much appreciated.

[ken2]

Last guy I had with a Marlin 300 with 3.3L F250's got OFS4 17 pitch and topped out at 5800 RPM 40 KTS
his response.
Props performed great offshore Sunday. We gained about 2kts overall in mid to low range and roughly .2-.5 MPG better. We are only able to turn the props 56-5700 wide open which doesn't concern me much unless that is a problem. We previously could turn the 3 blades 60/6100. Same 17 Pitch. The pick up speed and following sea ride is a world of difference. Thanks