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Discussion Starter · #1 ·
I'm trying to figure out the proper pitch prop for a 25ft 8.5 beam, 4,500lb boat. It only has a single screw 350. 260hp. any info would be great. thanks again
 

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Can't offer anything specifically, but I would look at some of the various online prop calculators, and consider what I like or don't like about my current prop, and go from there.

What is it you want that your current prop isn't doing?
 

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SMAN is spot on. If your 5.7 is stock (and at 260 hp it is) you won't want to push past 5000 rpm. A four blade prop will give you some additional bow lift and a little better out of the hole, but maybe a mile per hour slower than a three blade on the top end. I would recommend starting at a 21 pitch and go from there using the 150/200 rpm +/- rule noted in SMAN's post. The only way to know is to test props out, or join a forum of owners with boats just like yours and see if you can more specifics for a jumping off point.
 

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Discussion Starter · #5 ·
I checked a few of the online calculation sites out. I think I'm just gonna have to experiment a little. This tub just wont get up on plane, and i'm only gettin around 4100rpm top end. I'm thinkin its got a 21 on it now. might try a 19. Thanks for the help, Kinda missin the fast boat.....
 

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If she won't get up on plane then have you checked the hull for build-up. A dirty hull will eat up RPM's and keep you from getting on plane.

I have a 22ft with 8.5 beam and a 5.7L 260hp...about 4,000lbs. I'm running a three blade 19 pitch. Just for ref, she gets up on plane just fine but then again my hull is spotless.

Good luck.
 

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QUOTE(NOVA J @ Jun 29 2009, 10:08 PM) <{POST_SNAPBACK}>I checked a few of the online calculation sites out. I think I'm just gonna have to experiment a little. This tub just wont get up on plane, and i'm only gettin around 4100rpm top end. I'm thinkin its got a 21 on it now. might try a 19. Thanks for the help, Kinda missin the fast boat.....
IF you are satisfied otherwise, AND you don't have trim tabs, tabs would help and be a nice upgrade.

Just a thought.
 

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Before you go throwing props at it - Did you just get this boat? If not, is this a new problem? Is the engine properly tuned (ignition, fuel delivery, compression all verified good - she's an old girl, and may require some extra love to get her back into fighting shape)? Bottom clean?

Make sure your foundation is good before you move to re-propping it.....then start trying different props. But you are running the right prop when the engine reaches the factory specified WOT RPMs with your standard running load.

BTW- Heavy, a good 4 blade should give him some extra stern lift, we don't want more bow lift.
 

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Discussion Starter · #9 ·
The boat is new to me this year, so i'm still getting used to a few things, and I'm sure it I'll get her going good. gotta love it!...lol . the engine was completely tuned, and everything gone through a month ago. purrin like a kitten. so that should be good. trim tabs are working, although the tab switch with the indicator l e d's would be nice. I may have to get the mask and snorkel out, and scrub it as good as i can, I'm not planning on taking out of the water anytime soon. so and underwater bath may need to take place. I really think I'm gonna find the prop thats on there just isnt the right one. thanks for all the help. See yall at bell maer sat for the fw show!
 

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I dont know if you're still having this problem, but I went from a stock pitched 3 blade stainless (I wanna say it was a 19?) to a 4 blade 20 pitch stainless on my 5.7 with the alpha outdrive. I did lose some top end, but my hole shots are ridiculous now, ESPECIALLY pulling tubers and skiiers, and I get on plane pretty quick too. I had the luxury of trying 4-5 props before I settled on the one I have. I'd say a 4 blade 20 pitch is your best bet. You'll end up topping out at around 4300-4400 rpm (4600 is WOT on the 5.7).

This may be a dumb question, but are you adjusting your trim as you get on plane? I'm usually tapping it up almost as soon as I start getting on plane, and I notice I flatten out and pick up speed much faster.
 

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I assume this is a single prop and not a duo like a Bravo 3? Based on the pitches you are throwing out it looks like a single. Big difference in pitches.
 
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