Inboard Propeller Advice
#1
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We are here to help! Post on this thread or contact us directly for expert advice on Inboard applications.
For more detailed results for your particular application you can also fill out our online Inboard Propeller Sizing Form Located Here:

For more detailed results for your particular application you can also fill out our online Inboard Propeller Sizing Form Located Here:

#2
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Join Date: Jul 2019
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This is a question regarding outboard propellers but I was hoping that you could help anyway...I was ordering a replacement for my OEM propeller which was a 14 x 19, 3 blade propeller. My dealer mistakenly ordered a 4 blade 14 x 19.
I never took notice to my top end RPM’s with the old propeller, but now with the 4 blade I’m only getting 4900 RPM maxed and trimmed out with just myself on the boat. My engine is a 2008 Yamaha F150 four stroke driving a Scout 185. Per Yamaha - I should be getting 6000 max RPM.
The question is would a 4 blade vs a 3 blade with the same diameter and pitch make a difference for my max RPM?
Dealer is being good in that they said I could try the 4 blade and if I didn’t like it they would re order the 3 blade. I’m trying to decide if I should change the diameter or pitch to get closer to the recommended 6000 RPM.
Thank you!
I never took notice to my top end RPM’s with the old propeller, but now with the 4 blade I’m only getting 4900 RPM maxed and trimmed out with just myself on the boat. My engine is a 2008 Yamaha F150 four stroke driving a Scout 185. Per Yamaha - I should be getting 6000 max RPM.
The question is would a 4 blade vs a 3 blade with the same diameter and pitch make a difference for my max RPM?
Dealer is being good in that they said I could try the 4 blade and if I didn’t like it they would re order the 3 blade. I’m trying to decide if I should change the diameter or pitch to get closer to the recommended 6000 RPM.
Thank you!
#3
Member
Marine Advertiser
Thread Starter

Hello Mike
The equivalent 4 blade to a 3 blade 14 x 19 should be a 14 x 17, at the same speed and with similar rake, blade geometry ,etc. You might need less cup since the slippage would drop significantly with the extra blade.
Please let me know if further questions.
The equivalent 4 blade to a 3 blade 14 x 19 should be a 14 x 17, at the same speed and with similar rake, blade geometry ,etc. You might need less cup since the slippage would drop significantly with the extra blade.
Please let me know if further questions.
#6
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Marine Advertiser
Thread Starter

Hi mjugend2,
Props for boats with electric engines can be very tricky. We would be glad to do our best to help you determine the correct prop size, but we would need some more details and information. Please feel free to give us a call at 1-(800) 313-6025 and we will be happy to help.
Thanks!
Props for boats with electric engines can be very tricky. We would be glad to do our best to help you determine the correct prop size, but we would need some more details and information. Please feel free to give us a call at 1-(800) 313-6025 and we will be happy to help.
Thanks!
#7

As title states, I have a 43 Riviera that is in Puerto Vallarta and has two 23x25 Acme 1020 props. The original owner removed the original 3 blade props for these hoping to gain speed. The 4 blade ones are in pretty bad shape and they don't think they can be re conditioned. If I have to put new props on, I would rather have fuel economy instead of speed. What are your thoughts on this pleases? The boat weighs 34,000 lbs and motors are Catepillar 3208 turbocharged 465 hp models
#8
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Hello Underwaterhunt
I would repeat the Acme propellers, once the size has been confirmed (by doing a calculation) if they were working within the rpm and load parameters since these are very good propellers and usually are readily available.
Please contact our offices for price details and any other questions you may have.
We appreciate your business!
I would repeat the Acme propellers, once the size has been confirmed (by doing a calculation) if they were working within the rpm and load parameters since these are very good propellers and usually are readily available.
Please contact our offices for price details and any other questions you may have.
We appreciate your business!