Prop size

[Valiant Knight]

With my 5.2 m Valiant, fitted with a DF 90 Suzuki and a 13.25*17*3 Rubex prop from Solas, I get a little above 30 kts at around 5700-5800 rpm at WOT.
The rpm at WOT is above the recommended range for the engine (4500-5500).
Would a different prop size (diam or pitch) be recommended?

Thanks

Antonio

[Exe treme]

Hi Antonio

I know other factors can influence, but assuming your prop is in good condition, I would try a 19" pitch.

I run a 5.4m rib with Honda 90 outboard and 12.5 x 19 4-blade prop. I top out at about 36kts @ 5,800 which is right in my max rpm range.
My friend runs the same rib and experimented with a few different props, including a 17" pitch. He had the same issue as you with over-revving and low top end. He settled for a 13 x 19 3-blade and gets similar performance to me.

Hope that helps