most efficient operating range?

[L4Rosales]

I have an f-115 (2005). I have been wondering what is the most efficient operating range for the engine. (assuming it is propped right). I have looked, but I haven't been able to see anything published by Yamaha which shows info like that for their motors.
thanks,
Louis

[boscoe99]

Look at the Yamaha performance bulletins. You will note that on a single motor powered boat it is typically around 4000 RPM.

[wildturkey]

My yamaha 175hp 2 stroke purs at 4000 rpm. That is where I try to run it at all times. It uses about 10.5 gallons per hour at that speed on my totalizer readout.

[99yam40]

Just in case you have not seen this web site yet

Performance Bulletins | Yamaha Outboards

the boat you put it on and the set up makes a big difference also

[rodbolt17]

depending on jackplate and trim and trim tab position, my f150 likes 3200-3600 best.
typically about 6gph.