Prop selection

Designs for inboard or outboard power

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garobertson
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Location: Tyler, Texas

Prop selection

Postby garobertson » Wed Apr 18, 2007 6:58 pm

I'm building the Bass Boat (hull weight appros. 425 lbs) and have purchased a new Honda 40 hp motor but it did not come with a prop. Can anyone steer me to a prop selection guide or make recommendations?

The choices I have from the supplier I'm looking at (Overton's Marine) are:
12 1/4" 10 pitch
11 3/4" 12 picth
11 1/2" 13 pitch
11" 15 pitch

I don't need to be the fastest boat on the lake (fat chance anyway) but I don't want to take forever to plane, either.

Thanks for any suggestions
George

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kens
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Postby kens » Wed Apr 18, 2007 7:27 pm

Somewhere I have seen charts with weight recommendations for various size props for outboards.
I cannot remember if it was in the engine manual, or from the prop maker. Anyway, one of these should steer you towards a weight chart for prop sizing.

garobertson
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Joined: Thu Jun 22, 2006 1:06 pm
Location: Tyler, Texas

Postby garobertson » Wed Apr 18, 2007 7:41 pm

Thanks, Ken. I checked the "owners manual" first and only found info on changing the prop. I checked Overton's and went through their "Prop Selection Tool" which only led me to the choices for the right motor mfr and hp. and listed the choices above but did not consider weight or hull type.

I even stopped by my local "authorized Honda outboard dealer" today and they shrugged their shoulders. I told them I would check GlenL's Builders Forum and they said "Great idea". So, I'm looking for experience if I can't find facts.
George

Caber_Feidh
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Postby Caber_Feidh » Wed Apr 18, 2007 9:52 pm

Honda has their own strange final drive ratio, just to add some excitement to the whole mess.

Stock (USA version) it came with 11.25x12, Honda pn 58130-ZV5-000ZA or 11.5x10 (58130-ZV5-850ZA) Both are about 200$ here in the U.S.

The full range of what honda has mounted on them for various stock apps can be found at
http://honda.ca/MarineEng/Accessories/Props/Engines Navigate to the 40-50Hp section. Prices are full retail in Canadian$ (Not like that long list is going to help solve anything, but it may be nice to refer back to)
For some reason my boat was much faster before GPS came about

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kens
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Postby kens » Thu Apr 19, 2007 2:49 am

The Honda site didnt show you what you need. You're not gonna find the info you need from the sales store. You need tech info.
Go to http://www.midwestpropeller.com/
then scroll down to Michigan Wheel
http://www.miwheel.com/
There is a better selector for props by boat size. I clicked thru it and it came up with a 11x15. Check it out.
$102 from Midwest.

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tunahelper
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Postby tunahelper » Thu Apr 19, 2007 4:54 am

That will be a trial and error selection thing. All boat and motor combos will act different. Hopefully there will be a dealer in your area that will let you try different props. The fact it's a Honda there may not be that many used props to try. Are there any local dealers in your area that will let you try a few props providing you buy from them? You may be able to find a cheaper price online, but having a dealer let you try different brands will be worth the few extra bucks they charge.

basilkies
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Postby basilkies » Thu Apr 19, 2007 11:27 am

If your buying the motor from a dealer make a deal that he lets you try out props. If not find boats with the same motor and hull type as well as weight.

Now, here's what you "have to do".

Know your engines top RPM range it could be something like 5000 to 5500. In this situation you put on the prop and the average load you will carry most of the time. GO out and give it full throttle. The tach should read in the manufactures RPM range. In this case more than 5000 less than 5500. If it reads too high change to a higher pitch prop. Going up 1 inch more pitch is 200 less rpms. Going down reverse the process.

If your boat doesn't have a tach see if you can find someone with one of the ones you can temporarily hook direct to the motor. Maybe the guy you are buying the prop from has one.

Matching your prop and RPM's is critical to your motors lasting a long time. Even at slow speeds it insures that your motor is not being overworked or over revved.

garobertson
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Postby garobertson » Thu Apr 19, 2007 11:41 am

Thanks, guys. Lots of good info there. I'll see what I can get from a local dealer as far as different props to try.
George

Ron B
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Postby Ron B » Thu Apr 19, 2007 6:48 pm

they make a prop where you can change the bades to diffrent pitch or replace one if you hit a rock.( can also save your lower unit).ive ran one on my 85 johnson for the last 2 years and hae no comlaints. www.piranha.com

Caber_Feidh
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Postby Caber_Feidh » Fri Apr 20, 2007 10:25 am

I have had excellent luck with Piranha! they will trade blades as long as you haven't damaged them. pretty easy to put new blades on, and a spare set is a heck of a lot easier to carry than a whole prop.
For some reason my boat was much faster before GPS came about

garobertson
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Postby garobertson » Wed Apr 25, 2007 5:15 pm

OK, guys. Thanks for the input. Today I ordered a Pirahna prop. The sales rep was very helpful and also stated, as you have, that the prop blades are exchangeable for the life of the prop.

I'm looking forward to some happy boating soon...best get my Bass Boat done now!

Thanks again for the references.
George


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