What to do??

Ccfbailey

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Apr 18, 2013
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Someone please make my mind up for me. I've got a '13 Lund Rebel 1650 90hp 4 stroke. Running a Solas Rubex 4 blade 19 pitch. WOT is 6000rpm. I'm happy with overall performance but thinking I have some room to move in the rpm band. A good deal on a Trophy Plus 19 pitch ss has presented itself. Would that bring the revs down while increasing top end keeping the same pitch in a ss? A cheaper prop would be another Solas in a 21p 4 blade. Has anyone done this kind of comparison? Would love some opinions. Thanks
 
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Chris1956

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Mar 25, 2004
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A 3 blade prop would likely get you a bit more speed. Not sure if a 3 blade ss prop with the same pitch would lower your WOT RPM.

I would consider a 3 blade TP Hustler, in 21P.
 

Ccfbailey

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Apr 18, 2013
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Thanks Chris. The Trophy Plus is a 4 blade. The dealer selling it said it would lower the RPM and handle better overall. I'd like to stay with a 4 blade. Going to ask him if I can try it out first.
 

steelespike

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If you can test by all means test but what is the gps speed at 6000? What brand of motor?
 

Ccfbailey

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Sorry... Merc 90 4 stroke. 42 on Gps full trim. Fast hole shot. I'm happy with it but if it can be faster.... Hey why not
 

steelespike

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Another thought the Merc Spitfire 4 blade said to run the same pitch not having to lower going 3 to 4 blade.
I would think you could increase pitch 1 inch going from 4 blade to Spitfire 4 blade.I've seen a couple of independent
tests where the spitfire increased speed slightly on an already fast boat.
 

Ccfbailey

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I looked into a Spitfire 21p but they only go up to 19. My spare prop is a Spitfire 17. It seems to have a lot of flex in high rpm. I find my Solas doesn't. Leaning towards a Solas 4blade 21p. Seems big for that boat but what do I know??
 

gdpalumbo

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Mar 18, 2009
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Everyone I know that runs those 4 blades ends up going back to a 3 blade. Stainless does run better as it doesn't flex so it might bring down your rpms but I really doubt anything noticeanle. Also, they say if you move to a 4 blade you need to increase pitch by 2". I would stick with the 3 blade. Going from the 19 pitch to the 21 will slow down your hole shot a little bit but very time I've seen a boat go from a 19 to a 21 they've never lost enough hole shot to not be worth the gain in top speed which will be quite a bit. sure, the 19 will give you a better hole shot but if your bass fishing trounaments and such, the gain in top end from the 21 will be a pleasant increase and I think a good all around prop. The 4 blades will help with slip and the bite on the water but on that boat with a 90hp I would stick with the 3 blade 21. Also, remember there is a lot more to prop performance than just diameter and pitch, blade cupping and such matters as well.
 
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Ccfbailey

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Thanks for that input. I agree that 19p SS isn't going to change much and is likely a waste of money. A 21p is going on next for sure. Curious as to why your friends got rid of their 4 blades and went with 3's? Speed? I'm very happy with my 4 blade running in the Great Lakes. Would a 21p 4 blade be slower top end than a 3 blade?
Thanks
 
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littlerayray

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Feb 17, 2013
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I'm very happy with my spitfire hell I should work for merc the way I'm promoting it it's just to bad it doesn't come in the pitch you need
 

littlerayray

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My holes hot has improved my max mph has improved and I only lost maybe 100 rpm my max wot is 4700 instead of 4800 the boat doesn't wander as much at no wake speed and it runs smoother and handles tight turns much better also great handling when getting to the docks
 

steelespike

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If the 21" ss 4 blade knocks the rpm down 500( 2" pitch increase and ss prop loading the motor).
Testing the ss as 22" nets about 43 mph. based on the calculator I use.
And I wonder how the 90 will like running at 500 rpm less.
Obviously if the rpm holds up the results may be better.
 

Ccfbailey

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Thanks Steelespike. It hardly seems worth it when you put it that way. Is that calculation done using the numbers I've provided or is it a general calculatuion in comparing props? An increase of 1 mph is nothing really.
 

fishin98

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Nov 28, 2009
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. When I decided to go with a 4 blade...did some research...I found out when going from a 19p 3blade to a 4blade, you need to step down a pitch. Not listening I purchased a CompProp 19p 4 blade ( mistake) I was over reving my 90 Merc 2 stroke. Purchased a Solas Amita 4 blade 17p...Perfect...5800 rpm WOT,great Hole shot, was able to maintain plane at a lower rpm....Just my 2cts
 

Ccfbailey

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Apr 18, 2013
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Did you find out why the 19p 4 blade revs higher than your 17 p 4 blade. Different design? Diameter?
 

fishin98

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Did you find out why the 19p 4 blade revs higher than your 17 p 4 blade. Different design? Diameter?

Overall dia, and surface area .....You might want to find a prop shop that will let you experiment..I just found that the 17p 4blade met all my requirements.
 

steelespike

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I believe the Comprop Is a "plastic" prop. Sure to flex more than a metal prop.
 
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