NEW PROP QUESTION

[dragn3]

i am in the process of buying a new prop and was hoping for some input. for those of you that don't know, don't care or forgot i have an 88' 18' cc with a 96' merc 125. the current prop has no #'s stamped on it anywhere so i have no idea what size prop i am running now. top speed now is 32mph with 2 men and a full tank of fuel. i normally run about 5000-5200 rpms but wot is 5800. should i go three or four blade? stainless or aluminum? ??? thanks in advance for your input ;D

[spareparts]

there should be #'s somewhere, pull the prop off and look behind where the nut goes or look where the thrust washer goes. Worst case, carry it to a prop shop and have it checked. BTW some prop manufactures don't use the standard diameter/pitch identification( Michigan Wheels, maybe some others), you have to look up the prop part number to figure it out

[tsubaki]

Have you pulled the nut and washer off the shaft and looked to see if there is a size on the prop there? (same as spare :P)

[dragn3]

i have pulled it off and looked inside and out and there is no stamp identifying the diameter or pitch. on the outside of the hub between two of the blades there is this #- FE3442

[tsubaki]

Not that this explaines the location any better.
http://i175.photobucket.com/albums/w159/tsubaki3/Picture097.jpg
I have seen a few without identifying marks.

[tsubaki]

Right now I have no short answers to what prop size will work best. However I do suggest starting with the AL props and reserve the 4 blades for later experiments.
Try the prop charts for the size boat you got if no one comes up any better suggestions. I have seen it become expensive trying to arrive at the correct prop for a boat. Many times it's not just the prop that matters but how deep or shallow the motor is set and also how the weight in the boat is arranged.

[macojoe]

Wow thats a small prop for a 125??

[Skools Out]

http://www.iboats.com/mall/propfinder/?session_id=638381650&cart_id=42871

use this to see what you have with the numbers

[reelapeelin]

What concerns me about that prop is lack of surface...blades look narrow and looks like too much space between blades ... I'd be lookin' for a prop w/wider blades=more surface=more thrust ...

Stainless vs aluminum is a tuff question and depends on your use ...lots of shallow, hard bottom, I'd stick w/ alum. ... performance in open-water; hard to beat SS ...

At WOT, yer gettin' the right RPMs, so the pitch sounds right, but you gotta figure out WHAT it is ... prop-shop in your area?...

[Skools Out]

wrong prop guys that's not who's asking lol

[reelapeelin]

wrong prop guys that's not who's asking lol



Ooops :o ::) ...

[dragn3]

THANKS FELLA'S. YEA, THERE A FEW PROP SHOPS IN THE AREA SO I'LL JUST TAKE IT TO THEM TO FIND OUT WHAT I HAVE AND GO FROM THERE.

[tsubaki]

Wow thats a small prop for a 125??
From what I remember that was off a 1963-18hp evinrude. ;D I was just useing it as an example. ;D

[tsubaki]

Sometimes it's more cost effective to pay someone to find the correct one.
When my neighbor bought his Nitro it came with a Rapture prop (pretty)(have forgotten the numbers on the props, so don't cretique this)with a 21" pitch. The boat would do 52mph but it took 12 minutes (not really) to carefully get on plane without ventilating. The "mechanics" arrived that it needed a 19" pitch and installed it. This time it would quickly plane and have no ventilation problems but only do 43mph.
Wanting the best of both worlds, I peed him off and told him to get a jack plate (so as to be able to dig the foot deeper when starting on plane) and put the haul *** prop back on it.
He's considering it.
There are a lot of variables in choosing a prop, you'll be more satisfied finding the right one yourself but it is sure to cost you before it's over with. Paying someone gives you the convience of complaining and getting what you want and some experiance, if you remember the numbers.
And the obvious, aluminum is fine, stainless is usually better, 4 blades usually give better performance.
Remember the escape clause "usually". ;D
Oh and the same sized prop in AL will not necessarily perform the same way in SS. LOTS OF VARIABLES
Sometimes a "cupped" prop is preferred for performance, yet sometimes the smooth tipped ones do better.

[reelapeelin]

From what I remember that was off a 1963-18hp evinrude. ;D I was just useing it as an example. ;D




Thanks, tsubaki...I's thinkin' that looked like a funky prop for a 125 ::) ... ;D ...and I agree about gettin' "professional help" or assistance from witch-doctor ... there's black majic in props ;) ;D ...

[macojoe]

Posted by: macojoe Posted on: Jun 5th, 2007, 10:13pm
Wow thats a small prop for a 125??


I knew there wasn't something right in Denmark!

[tsubaki]

Oh and with the jack plate, that is not to say it will fix all problems just at best reduce them somewhat to a useable level.

[Blue_Runner]

The boat would do 52mph
This guy any kin to Skools Out? ;D

43mph sounds like a plenty to me 8)

[tsubaki]

Yeah me to. Daddy has an 14' Ashcraft that had a 90hp on it. While we were fishing in FLA he opened it up with me holding the gps, immediately we got to 54mph. When we got back he put a 50hp on it and stored the 90hp in my garage.

[dragn3]

has anyone ever used the prop wizard here on the web with any good results?

[tsubaki]

I've tried with no results. Figured it was me.

[reelapeelin]

has anyone ever used the prop wizard here on the web with any good results?




Don't know Prop Wizard, but I've seen these guys deliver!!

http://www.ptprop.com/

Click on "Need Help"






This is interesting

http://www.ptprop.com/technical-info.html

[spareparts]

http://sites.mercurymarine.com/portal/page?_pageid=126,53050,126_53052&_dad=portal&_sche ma=PORTAL

this is Mercury's prop selelector, works prety good, if the link doesn't work just search "mercury prop selector"

[reelapeelin]

So dragn...any ideas yet on which prop?... :D ...

[tsubaki]

I'm gonna throw some $.02 out there.
The ones available are a 15",17",19" & 21".
Well the 15" and 21" are out as far as I'm concerned. The 15" would be for slow and overloaded situations and the 21" would be for haul *** situations on a light boat , so neither apply. The 17" might be a good all around prop or the 19" may work if the boat isn't overloaded.
Need ya'lls input.

[Skools Out]

I'm gonna throw some $.02 out there.
The ones available are a 15",17",19" & 21".
Well the 15" and 21" are out as far as I'm concerned. The 15" would be for slow and overloaded situations and the 21" would be for haul *** situations on a light boat , so neither apply. The 17" might be a good all around prop or the 19" may work if the boat isn't overloaded.
Need ya'lls input.


Salt Water or Fresh Water? that makes a difference salt use 19 fresh use 17

[dragn3]

i just got back in town (and to my computer!) so at this point i am still doing some research for my prop. i've checked out the site's you all have given me for prop selection and also the prop wizard and they all pretty much tell me something different so i am going tommorow or the next day to talk to some folks at the local marine dealerships face to face to see what i can come up with. thanks again! here's the web site for the prop wizard that i used. ;D


http://www.ebuyers-boatprops.com/

[spareparts]

one thing to remember is to stay with the same style of prop when testing, sometimes when switching brands or styles, it can give completely different results. ( one of many examples)I was playing with a 26 Sea Ray once that had a 502, switched from a 21p Mirage(would hit revlimiter) to a 23 Vengence( only 23 I had), the boat wouldn't even plane off, kept blowing out. We had 23 Sea Craft that wouldn't turn enough rpm after we droped the engine one hole( coouldn't plane out in rough seas loaded), changed from a Mirage plus to a Vengence(same pitch), increased 400 rpm. Point is all the figuring and calculating you can do will only get you close, nothing beats bolting it on and trying it out. I would try a standard 19 P aluminum prop( QSS, Black Diamond, etc), there are planty around for you to try and if it doesn't work, they are easy to sell. Unless your running in a lot of sand, you probably will not be able to tell the difference between aluminum and SS. Check around for Honda props, some of them will go right on a Mercury( I know large hub for sure, not sure about small hub like your 125), they look pretty good, priced far below anything else, and their shape should create some good lift

[reelapeelin]

Keep in mind there are "stern-lifting" props and "bow-lifting" props ... which does your boat need ...and watch for these characteristics as you try different props ;) ...