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Author Topic:   SS Prop vs Aluminum
blackdog posted 10-25-2000 10:18 AM ET (US)   Profile for blackdog   Send Email to blackdog  
Is there a disadvantage to using a
SS prop? I guess if you hit something there is less give than an aluminum prop and could damage the drive?
Reliant posted 10-25-2000 11:51 AM ET (US)     Profile for Reliant  Send Email to Reliant     
Blackdog - I have used both aluminum and SS props. I love SS as there is much less cavitation which means better hole shots, better turning and better bite out in rough water. You are right in that it is my understanding that they are much stronger and if you hit something you are more likely to break something in the lower unit, which is going to be big bucks to fix. Much more then replacing or repairing an aluminum prop. The other down side of SS is that they cost several times what an aluminum prop costs new and the price to re-cup SS is higher as well.


Clark Roberts posted 10-25-2000 02:47 PM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
SS props are truely superior to al. props and well worth the price... cheaper in the long run if you run in shoal water with oyster bars etc... SS props , like al. props, are fitted with rubber mounted hubs designed to slip if something solid is hit... SS props can damage lower unit gears if idle on motor is set too high.. the constant "clunking" when shifting into gear can cause damage due to the mass of the ss prop... so set idle to lowest reasonable rpm!
Go Stainless.... Happy Whalin'... Clark... Spruce Creek Navy
blackdog posted 11-02-2000 09:49 AM ET (US)     Profile for blackdog  Send Email to blackdog     
Do you think switching to SS prop will void the MFG warranty? Should I use the same pitch as the Aluminum? Any suggestions as to where to purchase?
bigz posted 11-02-2000 12:32 PM ET (US)     Profile for bigz    
Gene -- no it won't void the warranty -- one thing though what are you achieving at WOT if it is on the high end of the soec you can go with the same pitch/dia in ss prop --- try here as a suggestion
bigz posted 11-02-2000 12:33 PM ET (US)     Profile for bigz    
oops that "spec"
blackdog posted 11-02-2000 02:02 PM ET (US)     Profile for blackdog  Send Email to blackdog     
Thanks BigZ. Not sure about speed @ WOT, no way to measure yet. The Prop I have is a 14x17 I think. I need to double-check that. Seems like it gets up quickly and top end speed feels good, running about 5600rpm @ WOT.
bigz posted 11-02-2000 02:22 PM ET (US)     Profile for bigz    
You appear right in the ball park at 5600 rpm -- I would just get the same prop in a ss --- others might have some ideas -- this is one of those performance areas which can drive one nuts tweaking props and listening ot the various opinions on what works or doesn't --- so just my two cents --- Tom
lhg posted 11-06-2000 04:08 PM ET (US)     Profile for lhg    
Regarding propeller selection, pitch and speed/hp considerations, I have just discovered on the revised website what I consider to be a great addition, for any brand engine user. It works kind of like finding an airline flight on Travelocity.
You fill out about 8 questions on your boat and HP configuration, and it will tell you speed, recommended pitch and prop style for your rig. You can play with any size HP engine, or twins, and find out what your boat will do. Since HP is HP, this should work for any brand. Just be sure your gear ratio is approximately the same as the equivalent Merc, regarding pitch choice, and you're in business.

Go to, and follow the link to Products, then propellers, then technical information. I think you have to accept cookies to get into this, but that's it. No sign in or anything like that.

jimh posted 11-06-2000 08:02 PM ET (US)     Profile for jimh  Send Email to jimh     
Thanks for the pointer to the Merc website. I followed you directions and got to the prop selector page--the URL was a mile long.

But I couldn't get it to work because my JAVA virtual machine complained:
"Applet PropSel can't start; error; java.lang.NoClassDefFoundError"

Anyone else have this problem?

Barry posted 11-06-2000 10:17 PM ET (US)     Profile for Barry  Send Email to Barry     

I recently invested in a SS prop for my '74 Montauk with '94 90hp Merc. The boat came with 21" and 19" aluminum props. With the 21" I was getting about 40 mph on the Hummingbird at 5200 rpm at WOT. The engine is rated for 5000 rpm. The 19" had some damage so I had it repaired. The first time out I got about 37 mph at 5600 rpm at WOT. Until I dinged it up that same trip :-(

So I shopped around and ended up buying a Stiletto. Even though most people recommended I stick with a Mercury prop. But since they weren't buying...

I had two different recommendations, one for the 17 and one for the 19. I went with a 13.25x17 thinking that the increased rake, cup, and efficiency would make it run like the 19" aluminum. Sure enough the numbers are almost identical.

The SS is significantly heavier and the "clunk" is more noticable. I probably need to adjust my idle speed down a little.

Anyway, I found the best deal at Bart's . Got the prop for $219.88. Overtons was $274.99 for the same thing.


Barry posted 11-06-2000 10:19 PM ET (US)     Profile for Barry  Send Email to Barry     
Oops, the engine is rated at 5500 rpm.
kingfish posted 11-06-2000 10:31 PM ET (US)     Profile for kingfish  Send Email to kingfish     
This post might be more appropriately placed in the for sale area, but this thread has reminded me that I bought a Stiletto for a 1989 100hp Merc I had on a 1984 Montauk. The "thunk" at shifting was so great that I took the prop back off after about five hours of use, and I think that I kept the prop when I sold the boat. I'll go snoop through the shed and refresh my memory as to the diameter and pitch; if anyone here might be interested in it at a good price, let me know.


triblet posted 11-06-2000 11:06 PM ET (US)     Profile for triblet  Send Email to triblet     
Jimh: my best guess is that their prop
selection Java applet requires a level of
Java higher than what you have (IE and
Netscape both still include 1.1.something
(1.1.5 for IE and 1.1.6 for Netscape).
Java is up to 1.3 now. You can download 1.3

Chuck Tribolet

lhg posted 11-06-2000 11:36 PM ET (US)     Profile for lhg    
Jim: Guessing at what you were going to look at on the Mercury prop site, I came up with the following for your 20 Revenge: (total loaded weight came up as 3650lbs for twin engine 20' Cuddy Cabin boat)

Twin Merc 60's 39 MPH
Twin Merc 75's 43 mph
Twin Merc 90's 49 mph
Twin Merc 115's 52 mph

Considering your Yamaha 70's are older, my guess is that they'll run about the same as the Merc 60's.

tbyrne posted 11-07-2000 08:47 AM ET (US)     Profile for tbyrne    
Jim, I had the same problem with the Merc website - it wouldn't let me input length or weight & therefore wouldn't calc.

As to the SS v. Aluminum thread, I just tried out a SS prop from Midwest Propeller and learned something new. I have a 2000 Sport 13 w/ the 25 Merc 4-stroke. It originally came with an 11" pitch aluminum prop that let the engine run to 6,200-6,300 rpm trimmed up with a light load. I went with a 12" pitch aluminum prop, which dropped the max rpm to about 6,000. I then tried a 13" pitch SS prop from Midwest Propeller in the hopes of getting to 5,700-5,800 w.o.t. and was surprised when the engine dropped all the way to 5,400 at w.o.t.

I called Midwest and they thought that the dramatic drop was due to the fact that the SS prop had greater cupping. Stainless can be bent further than aluminum without breaking, so a SS prop typically has more cup than the comparably sized aluminum prop. The extra cup "grabs" the water better, which lowers the rpm at which the motor can run.

Midwest has a very fair exchange policy & I plan to swap the 13" pitch for the 11" pitch SS prop, which should put me back in the range of 5,800 w.o.t. Hopefully, I'll get to test it out before winter really sets in.

blackdog posted 11-07-2000 12:07 PM ET (US)     Profile for blackdog  Send Email to blackdog     
Did you try changing the diameter?
jimh posted 11-07-2000 12:19 PM ET (US)     Profile for jimh  Send Email to jimh     
Couldn't get the latest-greatest JAVA from SUN, as they only had versions for SunOS/MS/linux, but I did get a newer version from Apple.

Then I had to get MS-Explorer 5.0, because my old faithful Netscape uses its own JAVA and can't use the external version.

So, after installing all that, I finally got to see the Mercury Propeller Calculator! But...

I still seem to have some trouble with screen redraws, where the black background covers the JAVA window. Probably due to the smaller monitor size I am using.

Argg! Stuff like this is one reason I try to keep this website running as simply as possible. It works for most any kind of browser, OS, monitor size, etc.

That website looks like they have poured plenty of effort into it. Maybe some day I'll be able to see more of the results!


lhg posted 11-07-2000 01:26 PM ET (US)     Profile for lhg    
Jim: Could it be a Pee Sea vs MacIntrash issue? It runs fine on my three year old Compaq Pentium 100 Deskpro with Win 95 and IE, with hardly any "bells or whistles."
tbyrne posted 11-07-2000 01:50 PM ET (US)     Profile for tbyrne    

I didn't see much room for variety in diameter in OEM/OEM replacement props. (I don't want to get into highly raked Ballistic/Stiletto props). There only seems to be slight variation in the available diameters, with higher pitched props having marginally smaller diameters. If you look at the available diameters for my motor, they only range from a max of 10 and 7/8" (11" pitch) down to about 10 and 3/8" (13" & 14" pitch).

Are you aware of other diameters, given the limitations inherent in the low h.p/small gearcase? Thanks for your interest.

Whaletosh posted 11-08-2000 08:56 AM ET (US)     Profile for Whaletosh    

I had similar experiance with my 13 Sport/25 four stroke. I tried a 4 blade 13 pitch Comprop, the results were terrible; slow to plane, WOT dropped to 5400 RPM, porpoising problems. Then I tried a 3 blade SS Mercury 12 pitch prop that my dealer leant me. Holeshot was just as good as the stock prop. Top end went up 1-1/2 to 2 MPH. I just didn't think that the price he wanted for a used prop was worth the little bit of extra performance. So I am sticking with the stock prop.

tbyrne posted 11-08-2000 02:14 PM ET (US)     Profile for tbyrne    
Whaletosh, I suspect 11" to 12" is the entire usable range in our case. The 25 is just not powerful enough to provide much latitude. Actually, if I hadn't been stepping down from an early 80's Outrage 18 with a 150 h.p. motor, I'd probably have less of that "ned for speed." I know that the 13 is already too fast for my son to ride in - he keeps telling me to "go slow, Dad." Now, if I can only keep him in that mindset when he wants to take her out ten years from now!
Ed Stone posted 11-15-2000 09:42 PM ET (US)     Profile for Ed Stone  Send Email to Ed Stone     
The alum. prop can be damaged at low tide
with just a few oysters or rocks.One oyster
and your motor goes to shaking.
What are those small rubber gromets in the
sides of some ss.props?How often should the
splines on the prop shaft be greased?
Is there a torque spec. for prop nuts?
Does anyone use the zinc prop nuts?
As far as ss. versus alum. props go,
after the alum. gets torn up,dig the
bottom out of your pocket and buy that
SS prop.
Ed Stone
Clark Roberts posted 11-16-2000 08:26 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Ed, if you are referring to the grommeted holes in the hub(one for each blade), these are for allowing air to blow over the blades to allow engine to rev up quickly. This is necessary for some high performance rigs, swinging very high pitch props, which can't plane out otherwise... The prop digs a hole and the engine revs way up and slowly the blades catch solid water and the boat climbs out onto plane.. the gromets (plugs) allow the user to elect to open or close these holes... An outboard prop acts as a simple screw at very low (idle) rpm,... then as the rpm increases, it acts as a "non-encased axial flow pump". The blades pull water in from the sides (not the front) and accellerate it to rear creating a jet (you can see this jet surface in mid wake). It's this action/reaction with the jet of water that propells the boat forward. The boat cannot exceed the speed of this jet of water!
The power of the engine and prop characteristics determine max jet speed. To increase the speed you have to increase hp or improve prop characteristics (and/or mounting set-up)... one way to increase speed of jet is to reduce the diameter of the prop.. less diameter makes for more speed, up to a practical point.... getting long winded here so will stop... bottom line, props are the most important single item (assuming engine in good tune etc) on your boat... just take the prop off and see how far you can go!!! That's my story and I'm sticking to it!! I have more opinions but fingers are tired.. heh,heh... Happy Whalin' . ,, Clark... Spruce Creek Navy
Clark Roberts posted 11-16-2000 08:33 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Should have said "to blow exhaust over blades" and not "air over blades"
lhg posted 11-16-2000 01:33 PM ET (US)     Profile for lhg    
Ventilated props, invented by Mercury, have now been in use for about 14 years now, beginning with the Mercury Laser/Laser II series. Until two years ago, the ventilation holes were of fixed size, cast into the propeller. Rubber plugs were offered to close up these holes for a few specialized applications, particularly with stern drive engines.

Two years ago Mercury came out with an improvement, with four different size plugs being available to fill the larger, round, cast hole in the props. This allows the user to select the amount of "over blade" exhaust ventilation desired by the user, for maximizing the boat/prop combination. The options are full plug, or small, medium & large vent holes. All Mercury SS props now are cast with these holes, except for the "elephant ear" Vengeance Series.

As Clark indicated, the ventilation allows the engine to rev up higher on take off, allowing quicker acceleration. Generally, the larger the hole, the faster the boat will accelerate, but the greater the boat speed will be needed to keep the prop from slipping. At all vent hole sizes, once the boat is doing over 30mph, the exhaust is bypassing the vent and is no longer flowing over the blade. On most boats, a vented prop, such as a "Laser" or "Mirage" will walk away from a traditional prop in the acceleration category. Do not confuse these with the non-hubbed racing props, often used by the Cigarette style boats, which will literally sit and spin, with great amounts of exhaust noise, until they slowing get underway. Those are only top speed props.

I run counter rotating ventilated Laser II
props on my 25 Outrage, and when accelerating, the engines pop right up to 3000 rpm (where they can quickly generate more HP) and the boat planes off. You can feel the tremendous acceleration as the props continue to dig in, necessitating a quick backing off of the throttles. People trying out the helm on my boat, unfamiliar with this type of operation, often find the boat speed running away from them before realizing to back off the gas.

Mercurys' general recommendations are that if you have a boat that will do over 40mph, you should be running a ventilated, higher performance prop, with the engine raised about 3/4". If you notice, all of the engine advertising photos, 75HP and up, show this style of prop on the engine. Unfortunately, all of these cost around $350-400 each. But in my estimation, well worth the expense. As Clark likes to say, the prop design is where the action is.

CDN posted 11-16-2000 04:00 PM ET (US)     Profile for CDN  Send Email to CDN     
For 18-25hp Mercury, including the 25hp Big Foot Four Stroke, and 20-35hp Johnson/Evinrude, Cabela's sells an SST prop for $199.99. They are available in 10", 11", 12", and 13" pitch for either, with different versions for Merc vs. OMC. If they work well, could be a good deal to get an SST prop for these smaller motors on 11'-13' Whalers. Page 27 on 2000 Marine Catalog.
Lowest price I've seen for a small motor SST prop.
Ed Stone posted 11-16-2000 10:04 PM ET (US)     Profile for Ed Stone  Send Email to Ed Stone     
Thanks for the prop lessons!
I think I'll leave the groments in for now
until I get accustomed to operating my 23.
The first few times I operated my boat I
gradually increased the throttles and the
bow jumped up and blocked my line of vision.
Now I've learned give it a good burst of
throttle then back off.
Ed Stone
Whaletosh posted 11-17-2000 10:12 AM ET (US)     Profile for Whaletosh    

Ditto, on the throttle, it is the same for most boats.

One of the mistakes new boaters make is to not shift into gear fast enough. they are trying to be to gentle. You want to put it into gear so that the shifting dogs aren't chattering, then give the throttles a good nudge. Lugging the engines at dispalcement speeds is bad for the motors (especially 2 strokes), wastes gas, blocks your view, and makes large wakes. So get the boat up
on plane thane back off, like you stated. Marine engines are designed for this.

P.S. Volvo-Penta cone drives shift much smoother. I believe some Mercruisers come with cone drives now as well.

lhg posted 12-11-2000 06:28 PM ET (US)     Profile for lhg    
Regarding the Mercurymarine website and their prop selector page, I have discovered that now the entire Mercury website cannot be accessed usless your browser is set to accept "cookies". Big mistake on their part as far as I am concerned, since this is only a product information site. My browser is set to refuse all cookies. I may now have to consider buying a Yamaha or OMC afterall!
bigz posted 12-12-2000 07:06 AM ET (US)     Profile for bigz    
Larry any reason why no cookies?

Sort of the way of life on the net and has been for a few years now ---

However, this little program makes us folks who are paranoid about privacy a little more secure --- try it you'll like it!

Then oh my you might not have to stoop so low as a Yam or OMC ;) TZ

whalernut posted 12-12-2000 08:11 PM ET (US)     Profile for whalernut  Send Email to whalernut     
Guys, how would I know if my computer has the Cookies program, I can surf the net but not very technical? Regards-Jack Graner.
Reliant posted 12-13-2000 01:04 PM ET (US)     Profile for Reliant  Send Email to Reliant     
Whalernut – If you are using either Netscape Communicator or Microsoft Internet Exploder to browse the web, they both have cookie capability built in. By default, these browsers are set to except all cookies unless you go into the preferences and change the settings to either prompt you before accepting cookies or to refuse all cookies.

As for as the utility that Bigz mentions, if you have not downloaded it and installed it, you probably do not have it.

I am going to have to try that utility myself. I have never had a problem with “malicious” cookies, but am always interested in good utilities to make the web safer for all.

Hope this helps,

Pete Ferguson

blackdog posted 03-15-2001 05:01 PM ET (US)     Profile for blackdog  Send Email to blackdog     
I’ve opened this thread up again because the weather is getting warm and I am about ready to pull the trigger on a SS Prop. I called Cabelas and they recommended 14 1/4 x 15 Rapture. I currently have the stock 14x17 Aluminum prop on the 16’ Dauntless, 115 FICHT. I thought I could just stay with the same size prop but the Cabelas guy said that the RPMs would go down. The Price is $299. We also spoke about a regular SS Michigan Wheel. I am not sure about their exchange policy. Any thoughts.


Barry posted 03-15-2001 05:48 PM ET (US)     Profile for Barry  Send Email to Barry     
Your RPMs MAY decrease due to increased cup and the resulting better bite of the stainless prop, but I wouldn't guarantee it. How close are you to the maximum rated RPMs for your motor with the 17"?
lhg posted 03-15-2001 07:00 PM ET (US)     Profile for lhg    
For the best prices I have seen on aftermarket SS performance props, go to The Stilettos are the same as the Raptures and this guy sells them for $219. I would agree that you should NOT drop down in pitch if the alum 17 is giving you correct RPM's. With a Stiletto or Rapture, you might want to lift the engine one bolt hole.
kingfish posted 03-15-2001 08:08 PM ET (US)     Profile for kingfish  Send Email to kingfish     
Seeing this post resurrected reminded me of the Stiletto prop I was going to dig up out of my shed - I have now dug it up.

It was used for about an hour on my '89 merc 100hp in-line six I had on an '84 Montauk; it is a 13.25x19, Stiletto ST11319. I bought it new for about $275.00 and will let it go for $150.00 plus shipping if it is of use to anyone. It is immaculate.

blackdog posted 03-16-2001 09:24 AM ET (US)     Profile for blackdog  Send Email to blackdog     
I am running 5600 rpms @ WOT. So the aluminum 14 x 17 is running around max RPM's suggested. Performance is good but I think it could be better.
Any vendors offer an exchange policy??

Thanks for the input


SuburbanBoy posted 03-16-2001 11:13 AM ET (US)     Profile for SuburbanBoy  Send Email to SuburbanBoy     
Specific Mercury dealers offer trials. Check their website (as I recall it is under Accessories)
Dick posted 03-16-2001 10:57 PM ET (US)     Profile for Dick  Send Email to Dick     
When I was a dealer I had a demo prop program and I would think any dealer interested in selling props would do the same. It's a simple matter of if it doesn't come back in the specified time or broken you bought it,guarenteed by a credit card number.
When you are looking at the price of props if you can't try you are not going to buy.
Don't hesitate to ask your dealer or prop shop for a demo.
blackdog posted 04-25-2001 10:03 AM ET (US)     Profile for blackdog  Send Email to blackdog     
Any body have preferences for a SS Prop as far MFG’s go? So many brands, Is / are any of them higher quality or is it just preference.
lhg posted 04-25-2001 02:47 PM ET (US)     Profile for lhg    
For anybody wanting to sell or buy a propeller, go to "". I have sold two Mercury 24" 4 blade Trophy props there, for $300 each, and the site works well. As a buyer, you must know exactly what you want first, then see if there is one for sale. You may be able to get a good deal on a used one. They keep 15% of the selling price, and re-imburse the seller the shipping cost, which is paid by the buyer. JCF, you could sell your Stiletto there in a week!

Blackdog - I assume your Dauntless will run about 40MPH with 115HP. You are just about at the break point where a performance SS vs a regular SS should be used. If you're looking for a little more bow lift, go with the performance lines such as a Rapture or Stiletto. Although Mercury now makes the interchangeable hub for their props (allowing them to be used on any brand engine), for mid sized 4 1/4" gearcases like yours, they don't offer the performance props until 20" pitch.
Here, once again, the experts are telling us something. In the Mercury line, you would use a non-vented Vengeance prop for your engine, either 16 or 18" pitch. Your gear ratios could make a difference here also.
Look into one of these for your OMC. The Vengeance is an excellent prop, and does give a little more bow lift than an aluminium.

For a Stiletto prop, nobody beats "", located in Indiana.

B Bear posted 04-25-2001 10:07 PM ET (US)     Profile for B Bear  Send Email to B Bear     
Thank you for mentioning the new Mercury props. I have a question about them.
I understand that the hub and prop housing are seperate not only to be able to make exchanges in housing (diameter and pitch) but also to help protect the lower unit from any damage, in that the housing will break away from the hub if it strikes something. Is this true, and if so would it be worth the extra cost? A Mercury prop for my boat would be $331.50, a Turning Point Express with the same system is $285. Props without this system, the stiletto from Barts is $235 and a local shop has Solis Titan for $249.99.
lhg posted 04-25-2001 11:11 PM ET (US)     Profile for lhg    
The newer Mercury hub design has replaced the rubber hub with a black plastic fitting that is removeable and would "shear" in the event of hitting something. It's easy to carry a spare for this, incidentally. From Mercury's current propeller catalog, they say:

"The Flo-Torq II (name for their interchangeable hub design) is also designed to resist slippage, yet still flex during engine shifting to cushion and protect the drivetrain from impact".

I do not know if the Stiletto brand has a cushioned hub to protect the drivetrain. Not familiar with the Solis Titan at all. I have heard of the Turning Point props, especially their new "performance aluminium" for about $90/each, but that is another subject. I was about to buy a set of Stiletto props for my 18' Whaler, mainly because of price, but from what I have recently learned about the ease of re-selling high quality Mercury props, (internet now makes this much easier) I am thinking it's smarter in the long run to buy the top of the line, which they are. Nobody, including other engine mfg's, knows props, or makes better ones, than Mercury in my opinion, especially when you get into SS and the higher performance models. There is a lot of info on their props at, including a pitch calculator (your browser has to be set to accept cookies to get on). They have a huge selection of styles, and their new adjustable venting system seems like a great feature, exclusively by Mercury. If you've ever had a boat with a Merc on it walk away from you, the Merc prop is probably one of the main reasons!

I should also mention that Mercury is selling some of their older style props, through the catalog houses, as "Quicksilver" props. these are similar in design, but not as highly polished, and with fixed, rather than adjustable, venting. Price only seems to be about $20/prop less than the Mercury line bought right, so I'm thinking it's no great deal. Aluminium, Vengeance, Laser and Mirage lines only, are available under Quicksilver branding, but they use numbers instead of names to identify them.

You'd think I worked for Brunswick, but I dont!! Just a fan of their propellers. I run a CR pair of Laser II's on my 25' Whaler, and no other BW that I've encountered so far walks away from me!

blackdog posted 05-04-2001 09:51 AM ET (US)     Profile for blackdog  Send Email to blackdog     
First of all I think you have sold me on Mercury props, I have requested a catalog!
I ran my Dauntless 16” last Sunday after I installed the GPS. I got up to around 40mph and then I trimmed up slightly and the speed jumped up to 45mph at 5750 Rpms with the 14x17 OMC aluminum prop! (Two people on board, 40 gallons of fuel) I had to back off the throttle a little to keep the Rpms from climbing higher. Pretty good performance, stable ride.
So you think the non-vented Vengeance is the best choice for my application. I am willing to invest the money for a quality prop. I would like to get on plane faster but I think a I am being critical as the bow really climbs in the air when you take off, it takes around 10 seconds or so to get on plane and I guess that is good. Just looking for your thoughts.
Thanks in advance.


lhg posted 05-04-2001 07:15 PM ET (US)     Profile for lhg    
Blackdog - It sounds like the 115 Ficht is a strong engine, and assuming 5500 is the redline, it seems you could use more pitch.

There are three possibilities, the safest being the 18" pitch Vengeance prop. These are good performers and will definitely improve overall performance, including hole shot, bow lift and speed. This is the highest pitch offered in the 4 1/4" gear case size. Prop part # is 48-16988A45, with hub kit #835266A1 (for an OMC engine).

Depending on the engine's gear ratio, which I don't know, it's also possible the engine will turn the more sophisticated, PVS vented, group of props, either the Laser II or High Five. These begin at 20" pitch, and it's possible your engine may turn one of these. The Laser is faster than the 5 blade, but if you need acceleration and exceptional smooth running, the 5 blade could really help. The venting (for acceleration) is adjustable, all the way from closed to a fairly large hole. Engine should probably be up 1 1/2" to achieve surface piercing and get the most out of one of these. Running them fully submerged effectively increases pitch by 2", and that would be too much for you.

A third solution would be to use a Stiletto 3 blade performance prop, since they make them in 19" pitch, which could also be just about right.

Clark, if you're following this, could you add anything here from your experiences, including the 5 blade?

Also, considering BW is shipping the Dauntless 16 with similiar HP Mercs, you might see what prop they are recommending or furnishing.

blackdog posted 05-07-2001 09:27 AM ET (US)     Profile for blackdog  Send Email to blackdog     
Thanks for the info Ihg. I believe the Owners manual gives 5750 as max Rpm's
Dan posted 05-10-2001 08:48 PM ET (US)     Profile for Dan  Send Email to Dan     
I test drove my 1999 Outrage 17 today in calm water, full tank of gas, myself and a closed sun top. 1999 Merc 115 25 shaft with aluminum prop 12.75x21. With engine warmed up, and test repeated 3 times, at WOT tach read 5200 and speed measured 45mph. What are your recommendations for a stainless prop. I'd like to get out of the hole faster. I want one of the new style Merc props with the plastic hub and a spare plastic hub.

lhg posted 05-10-2001 10:23 PM ET (US)     Profile for lhg    
Dan - Since your engine is rated at 5250 redline, you're in the right pitch range.
Your boat is fast enough that it can benefit from the higher rake and increased lift from a more modern prop, to raise more of the boat out of the water on plane. Your choices are the Laser II series or the High Five. The Laser will be a little faster, but the High Five will give you more hole shot and ultra smooth power. They are highly recommend for water skiing also, but hold well offshore too. So first you have to decide what is more important to you. The Laser II is one of Mercury's fastest props, with great bow lift. I use these and they are very nice.

Generally Mercury recommends that if switching from their odd numbered pitch aluminum props, you go up 1" in the performance enhancing series. So that would mean 22's. But you also have to raise the engine at least 1 bolt hole for this situation, so that the prop begins to operate surface piercing. If you do not raise the engine at least one or 2 bolt holes, and run the prop fully submerged, you should go down 1", and use the 20" pitch, since these things take a big "bite". Your top speed will still be the same, but you will gain the other benefits. You will have to experiment with the various (or none) venting sizes. I think the medium size plastic vent plugs come standard.

The best pricing I have yet to find in Merc props is with They will ship, with no sales tax, from FL. A Laser II will be $365 and a High Five will probably be about $390. Send them an e-mail for a quote.

blackdog posted 05-11-2001 09:13 AM ET (US)     Profile for blackdog  Send Email to blackdog     
I sent them and email. Thanks for the site. How long did it take for them to get back to you? I haven't heard from them yet.


lhg posted 05-14-2001 06:28 PM ET (US)     Profile for lhg    
They responded almost immediately, and the props were shipped the next day. So far, best service I have ever seen using E-mail.

These guys appear to be an excellent, highly competitive priced source for Mercury props.
Best I have found, almost $100 less/prop than others and my local dealers.

Dan posted 05-14-2001 08:56 PM ET (US)     Profile for Dan  Send Email to Dan     
Hi Ihg, this is Dan - again. Still trying to get a SS prop. One dealer recommended the 13x19 Laser -- do you think this one will work? How does one test out the vent holes? Many places that I've been asking for info are too busy this time of year to answer my questions or call me back.
Dan posted 05-15-2001 11:40 AM ET (US)     Profile for Dan  Send Email to Dan     
Spoke to a tech at Mercury this morning. For my 17 Outrage, 1999 115 Merc, 12.75x21 aluminum prop tach 5200, 45mph -- for better hole shot and better hold in turns -- they recommended a 13.75x19 Trophy Plus 4-blade stainless prop part# 48-825-932 A 46. This has the plastic hub. I asked about engine damage if I hit something stainless vs alum. They said the stainless weighs much more and it could do more engine damage - even with plastic hub.
lhg posted 05-15-2001 12:38 PM ET (US)     Profile for lhg    
Dan - Sounds like you're getting things narrowed down. The Dealer gave you wrong information, as for the 115 gear case, Mercury only makes a 20" pitch Laser II, not a 19. But if you want a Laser, that would be the way to go.

The Mercury tech recommendation sounds good also, as these newly designed 4 bladed Trophy Plus plops are supposed to be much better than the original Trophys. Dropping down to 19" pitch with one of these would be right also, as unless they are highly elevated, 3" or so, they take a big bite on the water, necessitating lower pitch. But they still have to be run at least 2 bolts up from the lowest position.

It's a toss up - The Laser II is a "safer", more tame purchase. But the Trophy Plus is a new design, and if being recommended by the factory, is worth something also. Those guys know a LOT more than I do! Both will give performance and holding you never knew existed, compared to the old fashioned aluminum you're used to. Check for trim tab interference. You may need one of the flat plates instead. Your best price will be those guys in Ft Myers FL.

Backlash posted 05-15-2001 01:12 PM ET (US)     Profile for Backlash  Send Email to Backlash     
My Laser II is a 19 pitch.
lhg posted 05-15-2001 07:29 PM ET (US)     Profile for lhg    
Steve - you're alive and well! Respond to our e-mails! It's boating season again, and Memorial Day is upon us.

For all of the large gearcase V-6 engines, most of the manufacturers use odd numbered pitches. As you know, I use 23's on the 25.

But the 115's are the mid size case (4 1/4" dia tube) and Merc sizes most of those performance props in the even numbers. I use 22" pitch Lasers on the 18.

Headed to FL to bring back the 25.

triblet posted 05-15-2001 07:58 PM ET (US)     Profile for triblet  Send Email to triblet     
I think a heavier prop would cause LESS
damage to the gear case. It is the rate
at which the prop gets stopped that causes
gear case damage. A light prop is going to
hit something and stop NOW. An heavy prop
is going to carve its way farther into the
something, and therefore slow down more slowly,
and therefore have less strain on the

Now, if the light prop breaks a blade early
and the heavy prop doesn't, the tables are


Blackeagle posted 05-16-2001 01:33 AM ET (US)     Profile for Blackeagle  Send Email to Blackeagle     
I'd think that aluminum prop would tend to deform when you hit something hard (say, a big rock). Thus even if it didn't shed a blade, it would probably come to a less abrupt stop than SS.
lhg posted 05-16-2001 03:17 AM ET (US)     Profile for lhg    
I think all this talk about "engine damage control" by using aluminum instead of an SS prop makes not much sense. I'm talking about boats that will do at least 25 mph here, where an SS prop can make a big difference to you in overall satisfaction of your rig.

I am convinced that an SS prop is MUCH more likely to get you home if you DO hit something. They are 5 times tougher and will stand up to 5 times more abuse, and can often be bent back on the spot enough to continue on, until a proper repair can be made. We buy insurance for serius damage to an engine propshaft if it should happen anyway. Don't see any reason for running around with less than maximum performance so you can save an insurance co a few bucks.

My point is why spend a fortune on your favorite pastime and recreation, then settle for the mediocre performance of a cheap aluminum prop, sacrificing a lot of the performance you paid to have, all because you think you're going to wreck a propshaft/gearcase. Are we all THAT careless on the water? Get out there, enjoy your boat and engine, be a good navigator and watch where you go, and don't worry about hitting a floating telphone pole. Get the performance and SECURITY you paid for. Don't skimp on a prop. If you're really going to trash a lower unit, such as running aground or hitting a submerged rock, it's probably not the propeller alone that's going to do it anyway. You're going to shear off the whole thing.

B Bear posted 05-16-2001 03:20 AM ET (US)     Profile for B Bear  Send Email to B Bear     
Outside of performance:

If a hard object were to be struck, such as a large rock or log, the most protective of the lower unit would be the comp prop first, aluminum second and after that stainless which would depend on the shear factor of the hub insert more than aluminum.

If a soft object were to be struck, such as a mud with pebbles, sand, small plants, the advantage would be in stainless where there would be no damage. While the aluminum would burr, blunt and or chip, gouge, unblancing the blades requiring replacement and the damaged prop to be refurbished (at around $50 min.). A few times at this and stainless becomes very cost effective.

So where you boat and how well you know your waters would be a factor.

jimh posted 09-23-2004 08:41 PM ET (US)     Profile for jimh  Send Email to jimh     
[Closed Thread.]

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