Stainless prop for Yamaha F25

[stever07]

1) Performance issue you are trying to correct.
Trying to get the most speed and take advantage of the remaining wot rpm.

2) Current prop manufacturer, model, aluminum or stainless as a minimum.
Turning Point Hustler aluminium, Yamaha aluminium previously.

3) Current prop diameter and pitch (required).
Turning Point: 10.375x11 Yamaha: 9.875x10.5

4) Wide open throttle RPM and speed with an average load (very helpful)
Turning Point: 5650-5750@26.7mph. Yamaha: 6200@27mph

5) Engine/drive make, model, year, and HP
2015 Yamaha F25

6) Boat make model, year, length and weight
2015 Lund SSV-14. 14'2"@300lbs

Went from the Yamaha prop that would overrev and initiate fuel cut to half inch more of pitch cupped with the Turning Point. With this change the boat handle better and is usable with just myself, had huge ventilation issues with the Yamaha prop.

Would like a recommendation for a stainless prop as my lake is very sandy and within a year eat the paint off my aluminium props. Would like to get some rpm back in the process. Not sure if I should drop pitch or stay at 11 and go stainless. Read so many contradicting statements, some say you gain rpm while others that you lose.

Currently interested in the Turning Point Express 10.125x11, good choice?

 

[steelespike]

It is often suggested to drop a 1/2" to an inch" when going from al to ss and with the turning point.
It appears you lost 450 rpm when going with an 11" TP prop I think a 10.5" will work better.
If all you are losing is paint Is the cost of a ss prop worth it.Do you see a difference in performance as the paint goes away?
Also when changing material it introduces another variable.

 

[Sea Rider]

What's the max wot range for that OB ? Experiencing ventilation/aeration issues when at tight close turns, running at choppy water cond ? probably badly trimmed along inappropriate transom height which will need to determine. Yam props don't have issues, if so, everyone owning a Yam OB will need to change prop asap. Boats generally have issues which needs to be fine tunned to match spot on any given brand OB.

Happy Boating

 

[steelespike]

My info indicates 5000 - 6000 rpm. on a 25 4 stroke.

 

[stever07]

It is often suggested to drop a 1/2" to an inch" when going from al to ss and with the turning point.
It appears you lost 450 rpm when going with an 11" TP prop I think a 10.5" will work better.
If all you are losing is paint Is the cost of a ss prop worth it.Do you see a difference in performance as the paint goes away?
Also when changing material it introduces another variable.

That's what I thought, will probably go with a 10" pitch.

I lost more than that, did some more runs today, 5600 is max WOT on a dead calm lake. Must have had the wind at my stern that first day.

What I'm not understanding is how I went from 6200+rpm with overrev protection kicking in going up half an inch in pitch and diameter with some cupping. Thats a 600rpm drop, quite a bit and not what I expected at all. Must be due to overall propeller shape.

I do lose performance, most noticably on hole shot, very sandy waters, eats propellers. Just want something that's going to last and I honestly don't mind spending the extra money.

 

[stever07]

What's the max wot range for that OB ? Experiencing ventilation/aeration issues when at tight close turns, running at choppy water cond ? probably badly trimmed along inappropriate transom height which will need to determine. Yam props don't have issues, if so, everyone owning a Yam OB will need to change prop asap. Boats generally have issues which needs to be fine tunned to match spot on any given brand OB.

Happy Boating

Internet indicates 5000-6000rpm, my owner's manual and dealer says 5500-6000rpm. I'm going with the latter.

Experienced ventilation with the Yamaha prop when lightly loaded in all conditions at all trim levels and in tight turns with a normal load. The Turning Point prop has completely eliminated this altogether.

Engine was rigged by one the most reputable marinas in the area, I realise this may not be saying much. Cavitation plate is roughly a half inch higher than the bottom of the boat trimmed fully in, runs visibly above the water at WOT. I have 5 trim positions, currently trimmed out second hole from completely in. One higher will induce a mild porpoise when I'm by myself, fine when I have a passenger.

I agree that usually Yamaha props don't have issues, but in thia case I do think it came propped wrong. This is my first small outboard due to HP restrictions, just trying to get the most out of it, so I'd like to be closer to 6000rpm at WOT with a stainless cupped prop.

I do believe that the cupping eliminated all of my ventilation issues.

 

[Sea Rider]

You should be trimmed for combo to ride parallel to water level and OB at 90 deg angle with respect to water level when on plane, play with trim holes to achieve this condition. Water flow passing at a exposed cavitation plate when on plane will produce unwanted ventilation/aeration issues at close tight turns and choppy water cond, will need to lower OB height to increase the amount of water under prop for prop to grip/bite much better more water. If the new prop has solved this issue good for you..

Happy Boating