Propeller change 3 blade or 4 blade?

[LeXXington]

Hi All:

So after many hours of use I need to change my prop. Nothing bad with the old one just a few chips from floating debris.

When choosing yes I could buy the same model, pitch, etc but I was thinking of going to a 4 blade.

Reasons. Lower speed plane, quicker hole shot stability.  I am less in the speed and more for stability.

 

Just wondering if any one has changed to a 4 blade prop or has one.  Your experience?

Gone through a few prop selector sites but they don't even recommend the prop that came with my boat any suggestions how to select the right size.

Thanks

 

 

 

[Terry]

Yup

 4 blade gives a more stable ride but a little less top end.  
but it’s more important to pick the right prop for your motor , your boat and the weight you carry on the boat 

[Fisherman]

Maybe I'm not looking at it in the same perspective, but what is the big hang up with holeshot?  Is it the look at me I can launch this tub out of the water or almost like "rolling coal".  Pushing the boat out of the water to launch to planning speed must put some extra stress on the transom for sure.  

[irishfield]

I have one of each.. lol

[aplumma]

1 hour ago, Fisherman said:

Maybe I'm not looking at it in the same perspective, but what is the big hang up with holeshot?  Is it the look at me I can launch this tub out of the water or almost like "rolling coal".  Pushing the boat out of the water to launch to planning speed must put some extra stress on the transom for sure.  

Think of it as the difference between a tractor and a car. The 4 blade will move more water meaning heavy loads can be negated so if you load up for camping, pull toys or have 4 adults they make it so you can accelerate to planing speed easier and then back off to get better fuel economy then 4 blades are preferred.  If you run light and are not pulling toys then the 3 blade is preferred  because you can increase top end and also economy by backing off the rpm's. The backing of of the rpm's is tricky because if you have a loaded boat and a 3 bladed prop the amount you can back off is less than if it is a lightly loaded boat. The act of having a blade cupped which accelerates the water off the tip can account for a higher top end as well. The material the prop is made of also affects the pitch needed , the stiffer the material like Stainless Steel  the less flex so the more efficient it is. For my 150 HP I have a 3 blade cupped S.S. prop because usually I have only 2 people in the boat. 

 

Art

[DRIFTER_016]

A four blade gives better holeshot, much better in cornering and the top end loss is negligible. 

At least on my 115 4 stroke. Also I can run my motor higher in the water column with a 4 or 5 blade prop which actually gives me more top end as I don't get slippage and cavitation like I do with my 3 blade props.

I currently have my 4 blade on as my 5 blade needed some tuning work done on it. I shipped it to Citywide in November and picked it up when I was down in December.

There is a big difference between my 4 blade and my 5 blade when it is tuned right. 

[Garnet]

Dog out of hole, blowing out are all just hard on your engine.

The correct prop should plane your boat at max operating weight and top speed should be just below your max rpm.

 

[misfish]

48 minutes ago, DRIFTER_016 said:

There is a big difference between my 4 blade and my 5 blade when it is tuned right. 

I was going to say a high 5, but unsure the motor Lex has . Had that on my 115 Mariner, 18 ft ranger . It was quick up and planed real nice . RPM at 58 mph was 5000-5300. Motor was humming just nice. Ask Terry, he was on it .LOL

[DRIFTER_016]

12 minutes ago, misfish said:

I was going to say a high 5, but unsure the motor Lex has . Had that on my 115 Mariner, 18 ft ranger . It was quick up and planed real nice . RPM at 58 mph was 5000-5300. Motor was humming just nice. Ask Terry, he was on it .LOL

Yeah I have a High 5 on my rig. 

Nice piece of metal. I got it at an even better price.

[kickingfrog]

3 hours ago, aplumma said:

Think of it as the difference between a tractor and a car. The 4 blade will move more water meaning heavy loads can be negated so if you load up for camping, pull toys or have 4 adults they make it so you can accelerate to planing speed easier and then back off to get better fuel economy then 4 blades are preferred.  If you run light and are not pulling toys then the 3 blade is preferred  because you can increase top end and also economy by backing off the rpm's. The backing of of the rpm's is tricky because if you have a loaded boat and a 3 bladed prop the amount you can back off is less than if it is a lightly loaded boat. The act of having a blade cupped which accelerates the water off the tip can account for a higher top end as well. The material the prop is made of also affects the pitch needed , the stiffer the material like Stainless Steel  the less flex so the more efficient it is. For my 150 HP I have a 3 blade cupped S.S. prop because usually I have only 2 people in the boat. 

 

Art

The only outboard I saw you drive had no prop at all.😮

[Garnet]

Hi was a great prop, I ran 1 on my Sprint for years.

If a boat is prop correctly you can't over drive it.

[aplumma]

12 hours ago, kickingfrog said:

The only outboard I saw you drive had no prop at all.😮

My name is Art an I have a boat addiction. With the variety of water I can fish from the ocean to small rivers nearby I have 4 boats. A 28 ft twin engine deep water boat, a 19 ft Ranger, A 18 ft jetdrive john boat and a 10 ft pontoon boat.  The boat you saw  is a great boat for shallow waters  with it's ability to run in 6 inches of water and reinforced bottom it can take a strike pretty well. It however is not happy with weeds which clog the intake and has to be cleared by hand. 

Art 

[LeXXington]

So basically my boat has currently. Merc 90 with a 13.25 and Pitch 17.

She moved very fast but with just me and the dog in it 90% of the time speed is not the issue.  Top speed is 37mph but hardly ever take it above 27mph unless perfect with no or little waves.

The prop selectors don't even recommend the prop I currently have so its a little bit confusing.

I would really like to be able to cruise  planing at a lower speed than 16mph.   Sure when there are no waves top speed all the way.

Edited March 17, 2020 by LeXXington
more info

[lew]

Paul, my last boat was a deep V Skeeter with a 150 Yamaha. The dealer told me he'd give me any stainless prop I wanted and seeing as I wanted the proper one for my rig I contacted Skeeter and they told me exactly which prop would be optimum for me and that's what the dealer put on it.

If you were to contact Princecraft and give them all your details I'm sure they could tell you the right prop for your set-up too.

And BTW, I've spent time in your boat with the previous owner and you've got an excellent ride there.

Edited March 17, 2020 by lew

[misfish]

9 minutes ago, lew said:

And BTW, I've spent time in your boat with the previous owner and you've got an excellent ride there.

I thought I knew that boat till you said that Lew . Johns old boat ?

[Freshtrax]

I switched to a 4 blade on my last two boats.  Night and day difference once you get the right prop. Both on plane and in rough water. 

What prop ,motor and wide open rpm you pulling now?     I have a brand new merc spitfire that was a little ambitious for my 115merc on a 20 ft boat.    i think it's a 17p and wouldn't turn enough wot rpm.   I ended up with a 15.   It may be a good fit.  your welcome to try before ya buy.  

[Freshtrax]

Just read the whole thread and ran out to the shop to check it.  It's a 13x17p  mercury spitfire.   If your close to your max rpm with the prop you have now it's probably a good fit.  

[captpierre]

Minimal trolling speed went from 2 to 2.8 mph going to 4 blade. Now need drift sock to slow down for eyes.   Better hole shot and lower RPMs at 20 mph. 

[Freshtrax]

5 minutes ago, captpierre said:

Minimal trolling speed went from 2 to 2.8 mph going to 4 blade. Now need drift sock to slow down for eyes.   Better hole shot and lower RPMs at 20 

Weird both my boats slowed down on the troll.  4stroke?

[LeXXington]

2 hours ago, lew said:

And BTW, I've spent time in your boat with the previous owner and you've got an excellent ride there.

Thanks Lew yes she is a great boat, a few more miles on her but still a solid ride.

I had an e-mail out to Prince Craft already still awaiting a response..  Guess they are not in a rush to respond to questions about a boat purchased in 2009

[LeXXington]

2 hours ago, misfish said:

I thought I knew that boat till you said that Lew . Johns old boat ?

Possibly  

[LeXXington]

1 hour ago, Freshtrax said:

Just read the whole thread and ran out to the shop to check it.  It's a 13x17p  mercury spitfire.   If your close to your max rpm with the prop you have now it's probably a good fit.  

That would be amazing PM sent

[LeXXington]

17 minutes ago, captpierre said:

   Better hole shot and lower RPMs at 20 mph. 

That's basically what I was looking to do.. I have a 9.9 for trolling I found the big engine just too hard to control the speed

[captpierre]

22 minutes ago, Freshtrax said:

Weird both my boats slowed down on the troll.  4stroke?

Yes. 115 4str Yammy. 

[captpierre]

9 minutes ago, LeXXington said:

That's basically what I was looking to do.. I have a 9.9 for trolling I found the big engine just too hard to control the speed

Hole shot not dramatically better but noticeable, especially loaded.