Prop for 23' Inboard Re-Power

[CValle]

What is everyone's experience with props for 23' inboard? Just repowered a 23' with a 300HP mercruiser with 1.5 to 1 gear and 1-1/4" shaft. The old prop was a 15-1/4x14 3-blade. Have been told to go to a 16x16. 4 or 3 blade?

[GetReel]

My records indicate the original spec was 16 x 17 3 blade with 5* cup and that's what was on mine. I am running a 16 x 16 4 blade on the same 1.5 gears. Max wheel size is 16 or the prop rumble will be overwhelming. I like the 4 blade, but you'll have to buy it 17 and have it cut down to 16 x 16, they didnt make a 16 when I did mine.

[CValle]

What kind of speed and rpm performance are you getting with the 4-blade. Thanks for the response. Appreciate it.

[aldo]

I'm running a 16 x 15 with a cup on mine.
Power is a 350/260hp Marine Power with efi.
My most efficient cruise is at 3400 RPM and 23 knots.
wot is 30 knots.
Curious how the extra hp moves the boat.

[aldo]

Also about the 3 vs 4 blade

[riprunner]

CValle,

The whole time I have had my 23 inboard I have not been happy at all with the performance. I started with a 15x17 and moved to a 16x17 per the stock specs and got the same exact poor performance. I was working the top of the engine too hard and wasn't getting anywhere near max RPM. Last fall I sent the prop out to Yohan in New Bedford and he changed the pitch and must have sprinkled some pixie dust on it. I only had a chance to take the boat out for a 20 minute run afterwards because it was the end of the season It was like a different boat, quiter, faster, more responsive, and better on fuel! I can't believe how much difference it made by making adjustments to an existing prop. I'll be back in hopefully this weekend, I'll post my new results soon. I'm located in Falmouth innner harbor next to pier 37.

[Gary Hill]

Mine has a 350 CARB, 315 HP and I have a 16 X 16 with a little playing with the cup to get the correct RPM 4600.
I usually run at 26 around 3100 RPM and 37 wide open with 3 people on it and get on the offshore trips for wreck fishing (don't usually turn it off unless I have another boat with me)I have gotten a lille better then two miles per gallon.

[aldo]

Gary,
Is that 26 knots or mph?
Either way, it's good. The extra hp makes a difference.

[Gary Hill]

@6 MPH, I use that because the couple of friends with SEE Vee's and SEACRAFT's ask what MPH and RPM's I'm running.

[MasterBaiter]

You and I are about the same. I'm not sure about my Hp. I thought I was lower (2V carb) and my speed is a little slower than you but I also get just over 2 mpg. As for my prop size - I have no idea other than 16". I want to change it for some stern lift and try for a little better milage so I am very interested in this discussion.