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#1
06-19-2012, 09:54 AM
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4 Blades on a 23CC
Anyone have any experience with a 4 blade prop on a 23CC. I'm having trouble getting on plane under a load with my 250 Yamaha 4 stroke, but I am still turning 4800 and its just not planing. My top speed is pretty good, I top out at 6100 RPMs and 36-37 kts. This is all with a Yamaha Saltwater Series 17 pitch, it has been refurbished, so I know that's a variable too. I'm pretty sure I'm at the right motor height as well. The cavitation plate is almost 5" above the bottom of the hull and it's obviously on a bracket.
I know we've been down this road a few times, I am just wondering if anyone has any before and after stats with the 4 blade... 
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#2
06-19-2012, 12:13 PM
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I have Hermco bracket, Yam 250 OX66, and Solas 4 blade 17P on my 23'. The bracket helps with stern lift also but I had the same engine/prop w/Armstrong bracket and it's more pronounced with Hermco.
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#3
06-19-2012, 02:54 PM
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Sounds like the motor is too high. With a bracketed, the anti-cavitation plate above the prop should be about 2-3" above the plane of the hull.
__________________
The Idiot Who Re-Built the Burnt-Up 35 Duffy
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#4
06-19-2012, 03:45 PM
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My cavitation plate is about 4" above keel, with three blade Im getting pretty solid bite with a standard 3 blade 17pitch 15.5" diameter. I originally had it 6" above (3' bracket setback).
I tested a 4 blade when the motor was 2" higher and I had a really good bite. lowering the motor may do it, a 4 blade might bite better too. I would contact propgods and see about trying a 4 blade
__________________
http://www.boatbuildercentral.com/  my rebuild thread: http://www.classicseacraft.com/commu...ad.php?t=22090
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#5
06-21-2012, 09:18 PM
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Yep ken would be a good place to start
__________________
Any way you measure it - dumbass is expensive
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#6
07-15-2012, 12:17 AM
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Power Tech makes a 4 blade stern lifting prop. That might help you out. I had problems with porpoising when I had a 225 Honda put on my 1989 23 WA. Put the 4 blade on raised the motor about 2 holes and that did the trick for me. I also have trim tabs but very seldom use them, maybe the little bit of extra flat surface helps out also.
__________________
Gary
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#7
07-19-2012, 03:17 PM
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i run a 4 blade merc rev 4 17p and love it, bracket is armstrong, motor 25", 275 verado which is heavy. i have zero issues getting on plane with or without using tabs. lost 2-3mPH topend, gained lower planing speed. i almost never run the 17p 3 blade tempest, its gathering dust.
dont go to a rev 4 15P per propgods, i forgot why though.
__________________
--------- 1977 Seacraft, Armstrong Bracket 275(chipped 250!) Verado Merc Rev 4 17P
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