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PROPS......2018 MB B52 23' 440


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#141 hawkdad22

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Posted 13 February 2020 - 06:27 PM

Raptor 400. We ride at near sea level. I was responding to dillyrev regarding elevation comment.

Altho I believe this prop is used as the “high elevation” prop

#142 hot4teach

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Posted 13 February 2020 - 10:51 PM

Raptor 400. We ride at near sea level. I was responding to dillyrev regarding elevation comment.
Altho I believe this prop is used as the “high elevation” prop


Do you have any vibration or other issues because of the prop being too close to the hull? I want your results. Just don't want to deal with any problems.

#143 hawkdad22

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Posted 14 February 2020 - 12:01 AM

I have not noticed any vibration. And I have not noticed any gel burn either. Tbag (earlier post in this thread) used the same size prop but slightly different pitch I believe and ended up having just a slight bit of gel burn so he installed a stainless plate on the hull above the prop. All depends on ur clearance.

#144 hot4teach

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Posted 14 February 2020 - 01:12 PM

I have not noticed any vibration. And I have not noticed any gel burn either. Tbag (earlier post in this thread) used the same size prop but slightly different pitch I believe and ended up having just a slight bit of gel burn so he installed a stainless plate on the hull above the prop. All depends on ur clearance.

 

Thanks. I just ordered a B52 so clearance will be the same.


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#145 Arkb52

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Posted 16 February 2020 - 07:01 AM

I'm going to keep the 2847 as a backup and sell the stock prop.



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Tbag, where did you pick up the stainless plate and what did you adhere it with?

#146 Tbag

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Posted 18 February 2020 - 07:20 PM

2247 to 2847 to 2849 each has about a 200 rpm drop at around 11mph. In general larger diameter props are more efficient at slow speeds and less efficient at high speeds. I'm getting better performance and fuel economy with the 15.5" props. I only get audible cavitation on the hull with hard turns at higher throttle.

The issue isn't necessarily cavitation it's that the cavitation bubbles can touch the hull when they implode vice imploding before they can touch the hull. I believe larger diameter props actually produce less cavitation for equal amount of thrust. The trick is to keep the thrust low enough that you don't create cavitation.

A 0.6mm stainless plate will protect the hull. Look on eBay- 3m 5200 works
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