1981 Johnson 25hp prop help

Dopemodz

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Jul 13, 2018
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Yes i have a 1981 johnson 25hp 2c short shaft. It has the exhaust port above prop. It has the stock prop that is a 9.2x14 13spline non thru. Its alittle beat up and im trying to find another 9.2x14 or a size i could use with my 14ft semi vhull aluminium boat. Ive found 9.25x12 but dont know if 12pitch would be enough for my boat. It does 20 3/4 throttle and 25 full throttle with the wore out prop. Would like to go alittle faster or the same.
 

Dopemodz

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Need prop info

I have a 1981 johnson 25hp with a 9.2x14 13sp non thru exhaust prop and im in need of a new one but dont know if i could use a 9.25x12 and it be near the same. The prop i have is stock from 1981 and its wore out and chipped. Its on a 14ft semi vhull aluminium boat.
 

Sea Rider

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Sep 20, 2008
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With a 12 pitch prop will achieve more wot rpm than with a 14 pitch, how much, can't possibly tell without a induction tach installed. If like boating heavily loaded combo will respond much faster than with a 14 pitch prop.

Happy Boating
 

jimmbo

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I have never heard of a 14" pitch prop for that engine. The engine was shipped with an 11" from the factory, the range offered by OMC for that engine stopped at 12"

We had a 79 25hp on a 14 ft hull and we used the 11" mirrocraft2a.jpg
 

Dopemodz

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I have never heard of a 14" pitch prop for that engine. The engine was shipped with an 11" from the factory, the range offered by OMC for that engine stopped at 12"

We had a 79 25hp on a 14 ft hull and we used the 11"

Thats crazy . Ill look again but most likely get a 12 pitch
 

jasper60103

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Sep 18, 2008
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A general rule is the heavier the load, the lower the pitch, and vice-versa . Also, you want to insure you're operating in the proper RPM range (4500-5500) at WOT. You should verify with a tach, not speed. There is a prop sub forum that can give better guidance than me though.
 

Dopemodz

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A general rule is the heavier the load, the lower the pitch, and vice-versa . Also, you want to insure you're operating in the proper RPM range (4500-5500) at WOT. You should verify with a tach, not speed. There is a prop sub forum that can give better guidance than me though.

Okay so if there is a non thru exhaust prop on the outboard is there anyway to use a thru exhaust even though the motor wont use it. Just hard trying to find a non thru exhaust 9.2x14 prop for my 81 johnson. It has the 13 spline
 

Sea Rider

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Sep 20, 2008
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Nope, both lower legs are quite different, can't interchange props between them. That's the issue of boating with Jurassic Outboards. Send current damaged prop to a prop shop and have it rebuilt to new condition.

Wot max revs as loaded is all, speed achieved is secondary...

Happy Boating
 

hardwater fisherman

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Mar 19, 2010
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Looking at the BRP website the 12 pitch is the highest pitch. I have a couple 10 pitch props for your motor but I have not seen a 14 pitch, I can not find a new 14 pitch for my 1976 40hp evinrude either. I am not saying that they dont exist but might be hard to find.
 

Dopemodz

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I will take a picture and saw yall tomorrow . it says 9.2x14. But im thinking get a new 12pitch and rebuild the 14pitch
 
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