What pitch do I need?

[Sportsman558]

I have a 17' Bluefin deep V aluminum fishing boat. I just bought a 1990 90 hp Mariner, but the prop did not come with the motor. I'm trying to figure out what pitch would be best for overall performance, and easiest on the motor. Thanks for the help, as I am new to boats, and trying to learn.

 

[steelespike]

Re: What pitch do I need?

If you read the stickies at the top of the page and fill out the form
it will help you understand prop selection better and help us select a prop.
Based on some limited research I would suggest a 17" pitch.Though you should wait for more suggestions.Some dealers will let you try different props if you intend to buy one.

 

[bryanwess2000]

Re: What pitch do I need?

Start with a 19p. That's what I had on my 19' starcraft with a 1991 merc90hp
and it jumped on plane and ran about 36mph gps before the number 2 cyl
piston ring gap made its way to the exhaust port. Sorry I don't have rpms I
lost the cyl before I got another tach.

 

[hwsiii]

Re: What pitch do I need?

Sportsman, You might try reading this for a better understanding of changing props for better performance, and for the major differences between aluminum props and stainless steel.

http://forums.iboats.com/showthread.php?t=369057

I show your boat to have a 2.3:1 gear ratio and a maximum RPM of5,000 to 5,500 RPM, I also show an allup boat weight of about 1,600# with two people,please verify this.

The prop you need will depend on what you intend on using the boat for, for all out speed you should expect to get about 42 MPH at WOT with a SS prop, but if you keep the boat loaded down or use it for skiing or other water sports you will need to trade some speed for extra thrust to accomplish this. Please let me know what your intended uses are and I will make a recommendation.



H

 

[Sportsman558]

Re: What pitch do I need?

I would say that 1600 is pretty accurate. I will use it mostly for fishing, but some tubing. My other question is: Is a steel prop better for the motor, as long as your not hitting anything?

 

[Sportsman558]

Re: What pitch do I need?

What diameter of prop would have come on my motor? Would a 13.25 diameter prop work for my motor?

 

[hwsiii]

Re: What pitch do I need?

Sportsman, as a normal course of events SS props provide more speed than aluminum. Depending on the prop a 13.25" diameter is in the range of props for your motor.


H

 

[Sportsman558]

Re: What pitch do I need?

So starting with a 13.25 x 17 Pitch should work? Or do you recommend a different selection? Thanks alot for the help

 

[hwsiii]

Re: What pitch do I need?

Sportsman, I received your PM but there was no other questions or answers in it.

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Old March 16th, 2010, 03:32 PM
Sportsman558 Sportsman558 is online now
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Default Re: What pitch do I need?
I would say that 1600 is pretty accurate. I will use it mostly for fishing, but some tubing. My other question is: Is a steel prop better for the motor, as long as your not hitting anything?
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H

 

[hwsiii]

Re: What pitch do I need?

We seem to be posting at the same time. LOL

Let me run some preliminary numbers and I will get back to you shortly.



H

 

[hwsiii]

Re: What pitch do I need?

Sportsman, for maximum speed for your boat I would recommend a Yamaha 19" pitch SS Painted steel prop, and for pulling skiers I would recommend a 17" pitch Solas Aluminum 4 blade if you have troubles pulling them up quick enough, but I believe for tubing you will be fine with the Yamaha prop and it will do double duty.



H

 

[Sportsman558]

Re: What pitch do I need?

So a Yamaha prop will fit my Mariner? What size diameter on the 19 pitch should I get? Thanks again!

 

[hwsiii]

Re: What pitch do I need?

I show them both to be 15 splines, but I am not positive they will interchange with each other. You need to go to the Mariner forum on here and ask that question, as well as on the Yamaha forum and ask them as well. You an also ask that question of a Yamaha dealer.



H

 

[Sportsman558]

Re: What pitch do I need?

I purchased a 13.2 x 19 Solas Rubex, She does about 36 with W.O.T at 5100 rpms. What pitch would give me more rpms? Thanks for the help.

 

[hwsiii]

Re: What pitch do I need?

Sportsman, for maximum speed for your boat I would recommend a Yamaha 19" pitch SS Painted steel prop, and for pulling skiers I would recommend a 17" pitch Solas Aluminum 4 blade if you have troubles pulling them up quick enough, but I believe for tubing you will be fine with the Yamaha prop and it will do double duty.

A 17" pitch Solas Aluminum 4 blade will bring your RPM to maximum.



H

 

[Sportsman558]

Re: What pitch do I need?

Should I set it up to run at max rpm or do you think I should just stay with what I got? Also would a 17 pitch Mercury prop do the same? Thanks alot for your help it is much appreciated.

 

[hwsiii]

Re: What pitch do I need?

Sportsman,

Should I set it up to run at max rpm or do you think I should just stay with what I got? Also would a 17 pitch Mercury prop do the same? Thanks alot for your help it is much appreciated

It needs to run at max.

No, buy the 17" Amita.

You are very welcome.

H

 

[dustedwatts]

Re: What pitch do I need?

I was curious, i have an older tri-hull, merc 120,,, 17 pitch prop, as it pulls a skiier like a dream, but am not hitting max rpm shoud i change to dif pitch prop, so i can reach max rpm... as i don't want to wear out then engine, and outdrive prematurely...

thanks

 

[Sportsman558]

Re: What pitch do I need?

Go with the Amita 4 or the Rubex 4 blade? Will I need to buy a new hub kit if I go with the Amita?The reason I was asking about a merc prop is because the rubber ring on the rubex does not seem like its a exact fit. Thanks again.

 

[dustedwatts]

Re: What pitch do I need?

I have a 1976 Tri-Hull 120 Merc 1.98:1 Gears, running a 19 prop right now, hole shot is kinda slow, wot hits 4500 rpm, somethimes 4800(glass water)
What prop would you all recomend?


Thanks in advance.