2009 SEA RAY 350/370 RPM & PROP...

[Soundman]

2009 SEA RAY 350/370 RPM & PROP QUESTION

I own a  2009 350 / 370 Sundancer with Bravo 3 Axius stern drives and 496mag engines . When I plane the boat at full throttle the max rpm's I get from each engine is about 3900-4000, the boats max speed is 38-40 MPH . A friend of mine has suggested that I should be getting much higher RPM from my engines, close to 5000 and that I may have propeller issue . The previous owner of this boat informed me that he had the props "cupped" to increase efficiency, I know nothing about this process and what the effects of this prop modification is.  Anyone have this boat and have any experience with what the top end speed & rpm should be ?

[Ynot]

I have a 2011 390 same power and drives I get 4600 rpms cruise at 3900 at 25 mph

[Brite_Idea]

WOT should be 4400-4800 and as close to 4800 as possible. Cupping the props give them more bite but lowers WOT, If you are sure that your engines are running as good as they can then you need to think about reducing the prop set pitch by at least two or three inches. Every inch of prop size change will give you a two hundred RPM increase. A good prop shop will let you try a set before buying them but you'll have to change the props in the water or haul the boat to do it. Also you have to know what size you're running now?