any boat guys ,, prop question

[Voodoo]

On 7/2/2023 at 6:03 AM, polaris7541 said:

k getting confused is a 21 pitch faster than a 19

Pitch is the theoretical distance the prop will move in one full turn.

19 = 19 inches forward in one turn and so forth.

 

[polaris7541]

that's what i thought , this 17 i was advised to buy is going to be a tork turd , good thing the company has a exchange program , just have to pay the shipping there,, DAMMIT

[EvilBird]

53 minutes ago, polaris7541 said:

that's what i thought , this 17 i was advised to buy is going to be a tork turd , good thing the company has a exchange program , just have to pay the shipping there,, DAMMIT

Yeah 17 will make it rip on plane fast but after that id think with that boat and engine it will hurt your top speed. 

like i said before maybe look into a 19 4 blade for best of both worlds . 

[EvilBird]

On 7/2/2023 at 6:03 AM, polaris7541 said:

k getting confused is a 21 pitch faster than a 19

if your motor can turn a 21p in theory it could be faster yes . 

But the hole shot will suffer more than 19p 

[polaris7541]

what's the advantage of a 4 blade

[Voodoo]

6 hours ago, polaris7541 said:

what's the advantage of a 4 blade

 More "traction" with the water but comes with a cost of friction.  

3 blades is the compromise between speed and thrust.

[Crnr2Crnr]

fwiw... 16ft Skeeter Bass Boat with 85hp Yamaha triple and what works best for me.

Quicksilver Nemesis 4blade aluminum 15P prop.  Quick out of the hole and holds extremely well in turns.  Used when pulling kids on the tube or skiing and more than one person onboard.  In other words under heavier loads.  Will exceed RPM at wot (blow out) with light load and just driver.  

Quicksilver Nemesis 4blade aluminum 17P prop.  Run this the vast majority of the time for fishing and running up and down the river.  Max desired RPM and trim easily attained.  

Also have a 19P stainless 3blade which came with the boat.  With just myself onboard it runs the fastest with this but has to be trimmed just perfectly or the boat will porpoise.  

Weight onboard (load) is the biggest variable for trying to find the ideal prop.  For the money and based on my own experience having several boats and testing numerous props on a river where you're likely to tag a submerged log on occasion the Nemesis works great for me... as a throwaway prop when damaged.  Stainless are the best for holding speed but are heavier and often people overprop their rigs thinking they can go from aluminum to stainless with the same pitch.  You want to be able to run max rpm.

Lastly, for me I'd rather throw an aluminum prop in the trash than trash a lower unit with a stainless prop.

https://www.quicksilver-products.com/en/product/nemesis-4-blade-aluminum-propeller

 

 

Edited July 6, 2023 by Crnr2Crnr

[polaris7541]

sent the 17 back for a 19 and also bought a 21 will see the results , the prop that came on the boat was a 14.5x 19  ,, i ordered a 14.125x19 and a 14.125x21 ,, these blades on these turning point prop are twice the thickness of the one i took off ,, also weight a lot less they also have holes in the hub for the water to escape ,, they are not supposed to flex like aluminum,, so im thinkin between the 2 , it should give what i want ,, thanks for all the input guys

[Guest]

28 minutes ago, polaris7541 said:

sent the 17 back for a 19 and also bought a 21 will see the results , the prop that came on the boat was a 14.5x 19  ,, i ordered a 14.125x19 and a 14.125x21 ,, these blades on these turning point prop are twice the thickness of the one i took off ,, also weight a lot less they also have holes in the hub for the water to escape ,, they are not supposed to flex like aluminum,, so im thinkin between the 2 , it should give what i want ,, thanks for all the input guys

The first thing you have to do is have a prop that will allow the motor to reach peak rpm. That is priority #1 and why I suggested 17 or less. If you're not making power you won't make speed period. All this flex stuff is secondary and more like fine tuning. You need way more rpm and that means less pitch.

[Crnr2Crnr]

24 minutes ago, polaris7541 said:

sent the 17 back for a 19 and also bought a 21 will see the results , the prop that came on the boat was a 14.5x 19  ,, i ordered a 14.125x19 and a 14.125x21 ,, these blades on these turning point prop are twice the thickness of the one i took off ,, also weight a lot less they also have holes in the hub for the water to escape ,, they are not supposed to flex like aluminum,, so im thinkin between the 2 , it should give what i want ,, thanks for all the input guys

I went back and reread your posts... Frankly imo you are over propped and not turning enough rpm (regardless of hp).  You don't want to lug the engine (overgear) it with a higher pitched prop.  There was plenty of good advice from others with experience and I agree with them and that you should have tried the 17P.  If you have a prop shop or good dealer they might have test units to try if you buy from them.  People get focused on top speed in boats that aren't performance or speed boats and over prop them.  So again, as others and I pointed out you need to figure out exactly which engine it has, the engines target rpm range and prop it accordingly... which in your case is probably going down in pitch to 17P in my opinion.

[Crnr2Crnr]

3 minutes ago, HSR said:

The first thing you have to do is have a prop that will allow the motor to reach peak rpm. That is priority #1 and why I suggested 17 or less. If you're not making power you won't make speed period. All this flex stuff is secondary and more like fine tuning. You need way more rpm and that means less pitch.

Exactly... seems most of us are of the same mindset 

[krom]

On 7/2/2023 at 6:03 AM, polaris7541 said:

k getting confused is a 21 pitch faster than a 19

Depends...

If the engine has enough power to pull the increased pitch, the boat will go faster.  If the engine doesn't have enough power, it will go the same speed, or slower, potentially causing engine damage

[krom]

45 minutes ago, polaris7541 said:

sent the 17 back for a 19 and also bought a 21 will see the results , the prop that came on the boat was a 14.5x 19  ,, i ordered a 14.125x19 and a 14.125x21 ,, these blades on these turning point prop are twice the thickness of the one i took off ,, also weight a lot less they also have holes in the hub for the water to escape ,, they are not supposed to flex like aluminum,, so im thinkin between the 2 , it should give what i want ,, thanks for all the input guys

Turning point are aluminum, and flex like any other aluminum prop

thicker blades have lower performance

holes have nothing to do with water.  they are there so exhaust can ventilate the prop, cause it to slip, and get the engine up in rpm quicker.

You seem lost on this entire process.

The only thing that matters is that the engine is turning at the top of the correct RPM range with one person and a light load of fuel.

[Crnr2Crnr]

26 minutes ago, krom said:

Turning point are aluminum, and flex like any other aluminum prop

thicker blades have lower performance

holes have nothing to do with water.  they are there so exhaust can ventilate the prop, cause it to slip, and get the engine up in rpm quicker.

You seem lost on this entire process.

The only thing that matters is that the engine is turning at the top of the correct RPM range with one person and a light load of fuel.

otb... just like clutching a sled for many

 

 

[Deephaven]

And not enough RPM means you need to prop down or that you have something else catastrophic with the boat.