Prop optimization for Yamaha F130AETL / Zar 53

[VelVel]

Hi,
I'm currently running a ZAR 53 RIB with a Yamaha F130AETL outboard and a 4-blade stainless SOLAS 14×19 (9453-130-19) prop. The boat runs about 70 km/h / 5500 RPM @ WOT.

The next SOLAS 4-blade propeller with lower pitch would be a 13x17. By rule of thumb, this would be +400 RPM. The optimum full-throttle range for the engine is 5300-6300 RPM. A 15-pitch prop would hit the limiter and therefore not be a sensible option.

Is there still some optimization potential for low-end thrust by going to the 17-pitch? Or would I sacrifice my fuel economy / top speed?

[Limecc]

Just mentioned this in another thread. Getting the engine height optimised could be worth one or two pitches in prop. If it's too low and overpropped, when at the right height it might pull max rpm with what you've got already. Have your cake and eat it.

Have you experimented with the height? Don't rely on the previous owner or even that the workshop which rigged the engine getting it right. They always err on the safe (too low) side. Needs to be as high as possible without ventilation.