Need Prop for 23' CC w/ Yamaha 250 HPDI 30"

[kglynn]

What prop should I put on this boat?

Thanks kev-

[zup]

I have the same set up and have tested two props to date. A 19 inch SS yamaha Salt Water Series will turn 4900-5000 WOT at 46-47 MPH per GPS. A 17 inch SS yamaha Salt Water Series turns 5300 WOT at 44-45 MPH. I prefer the 19 myself as the cruise speed is about 5 MPH faster than the 17 at the same RPM, due to difference in pitch, also the 19 max GPH is around 2.8-3 MPG at 28 MPH, the 17 is 2.4-2.6 MPG at 26 MPH.

I am going to try an 16" and 18" powertech 4 blade in the next few weeks, I will let you know how it works out. But if I had to choose right now I wuld take the 19". It falls right in the middle of the operating range (4500-5500) at right at max HP (5000 RPM). Also, it provides the highest cruise speed and best MPG.

Hope this helps.

[FELLOW-SHIP]

Ha KGLYNN
I have a 225 Yamaha 30” and run the 17” I like that one the most gives me the correct rpm’s for the motor I also have a 18” three blade for my backup.
FellowShip [img]/images/graemlins/grin.gif[/img]

[thedink9]

Zup
I assume you have the engine on a bracket. Should I expect the same performance out of a 250 with a 25" shaft and 19 pitch prop, when it's mounted on the transom?
Does anyone have a 250 on their transon?
Thanks Dink

[Capt Chuck]

Kevin

I'm Running a 25" shaft 250hp with a 3 blade S/S 17" Viper Prop without a bracket on my 23'. I have a T-Top, full fuel of 135 gal and 15 gal water and equipment:

According too GPS and system matched gauges, here's my numbers. I will match these numbers again later this year after mounting the same motor and prop on the Potter Bracket:

RPM GPS MPH
3500 13.5 (not planed off)
4300 30.0 (cruise)
4500 33.4
5000 37.9
5400 40.5
5900-6000 46.0 (Trimmed)

Don't shoot from the hip you can get some test props from your dealer and try them out and then purchase the S/S expensive one that gives you the best performance.

[thedink9]

Cap't. Chuck

Do you believe the 17" is the right pitch or should I consider the 19". I have the same basic config. ( T Top, 130 Gal . tank) as you, but don't have the ability of trying a few test props. I want to get this right the first time.

[Capt Chuck]

Dink

I tried the 19" on my old 225HP and again on my 250HP. I could not muster the rpm's that I needed. I am not a performance guru here and some other members are much more versed like "Briguy" but if I had no way to try different props before purchase I would go for the 17" based on the numbers I posted above. [img]/images/graemlins/wink.gif[/img]

[thedink9]

Cap't Chuck

What is the diameter on your prop?

Dink

[Capt Chuck]

dink

14 3/4 . It should not make a difference in the numbers but don't forget I have an OMC power plant not a Yami' [img]/images/graemlins/wink.gif[/img]

[zup]

My motor is on the transom. I ended up going with an 18" Powertech 4 blade. Will 130 gallons of fule and 2 people it turned 4900 at 44 mph.