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Author Topic:   Mercury FLO-TORQ Hub Adapter for Yamaha Outboard
elaelap posted 12-30-2005 01:01 AM ET (US)   Profile for elaelap   Send Email to elaelap  
Through the usual generosity of one of the CW members, I just received a brand new 13" diameter, 18" pitch Mercury Vengeance stainless steel three bladed prop to try out on my 2004 Yamaha 115 four stroke EFI motor/1988 Outrage 18. I've been running the stock Yamaha 19" black stainless prop, but I'd like to get a couple of hundred more turns out of my motor wide open, so I'm gonna try this one out when the weather lets me. The donor (you all know him, but I'll let him identify himself if he chooses) kindly said I could try out the prop 'on approval' and if it works well, pay him the very modest amount he bought it for on ebay; if it doesn't, just send it back. Can't beat that!

My question is: The new prop was accompanied by a Mercury Flo-Torq II hub kit (835257K 1), which may not be designed to fit my Yamaha motor. Any specific information on what kind of conversion hub kit I'll need (and its approximate cost) would be appreciated, as well as advice on the best place to purchase it. I don't want to just walk into my Yamaha dealership unarmed with some facts and prices, if you get my drift.

Thanks in advance to all, and special thanks again to the thoughtful donor. I'll report on my tests when the weather breaks, if it ever does.


Dick posted 12-30-2005 10:13 AM ET (US)     Profile for Dick  Send Email to Dick
click propellers and then parts express.

They list the hub kit as #835271Q2.


elaelap posted 12-30-2005 11:04 AM ET (US)     Profile for elaelap  Send Email to elaelap     
Thanks as usual for your help, Dick. You probably don't remember, but you were one of the very first CW members to help me with advice on several other matters when I bought my first Whaler more than three years ago. Hope things are going well for you, and that your woodworking business is giving you pleasure. I still have that beautiful Whaler wood pen that you turned lashed to my dry log with a length of marline so it won't get lost...I think it's the only pen I've ever owned without losing within a couple of weeks since I was in grade school.

Best wishes for the New Year, my friend.


Peter posted 12-30-2005 11:20 AM ET (US)     Profile for Peter  Send Email to Peter     
Tony - Hub kits cost in the neighborhood of $40. After you have installed the prop and have run it once, recheck the prop nut torque as I found one of my propeller to be loose after the plastic sleeve seated further into the hub after the first run.
ratherwhalering posted 12-30-2005 01:11 PM ET (US)     Profile for ratherwhalering  Send Email to ratherwhalering     
Tony, that part is available at your local West Marine. ProductDisplay?storeId=10001&langId=-1&catalogId=10001&classNum=190& subdeptNum=189&storeNum=6&productId=130265

ratherwhalering posted 12-30-2005 01:13 PM ET (US)     Profile for ratherwhalering  Send Email to ratherwhalering     
Scratch that link...wrong part number.
elaelap posted 12-30-2005 06:31 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Thanks Peter...will do. And we'll talk again soon, Rob.


jimh posted 12-30-2005 08:31 PM ET (US)     Profile for jimh  Send Email to jimh     
Investing in a FLO-TORQ-II hub kit for you outboard motor is not a bad idea. Having one allows you to test and run just about any of the Mercury propellers. As mentioned, they are about $40 and are very widely available just about anywhere Mercury products are sold.
elaelap posted 12-31-2005 12:38 AM ET (US)     Profile for elaelap  Send Email to elaelap     
Jim, thanks and as I stated above, "The new prop was accompanied by a Mercury Flo-Torq II hub kit (835257K 1)."

Are you saying that with this hub kit I've already got what I need? Are there different Flo-Torq II hub kits for different motors, or is the thing I've got some sort of universal adapter? I'm concerned since the large box the prop came in has the following printed admonition: "If purchased for a non-Mercury engine, see your dealer for the appropriate hub kit."

I'm dying to get outside and fool around with the new prop, but we're in the midst of a very serious storm out here, with substantial flooding and power loss, and I'm awaiting some dry weather to yank the old prop and see if this thing fits. I'd sure like to know definitively one way or the other.


Peter posted 12-31-2005 07:59 AM ET (US)     Profile for Peter  Send Email to Peter     
Tony - According to Mercury's application chart, part number 835257K 1 is for a Mercruiser outdrive. The part number you need is the one specified by Dick.

There are different hub kits for different brands of outboards. The plastic drive sleeves that fit inside the propeller hub are the same in all of the kits but the combination of the forward thrust washers, the aft adaptor, the aft spacer/washer and the nut are different between the different brands of outboards. This is because the propeller shafts between the brands are different lengths and shapes.

jimh posted 12-31-2005 10:00 AM ET (US)     Profile for jimh  Send Email to jimh     
Tony--the propellers are more or less universal. The hub kits are specific to each motor. Usually there are one or two hub kits available for each brand of motor, and they vary with the horsepower or style of the gear case for particular models or ranges of horsepower.

Once you get a hub kit for your Yamaha motor, you will be able to use just about any of the Mercury propellers on your motor.

Tom W Clark posted 12-31-2005 10:02 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
This is really confusing but I suspect that what Tony has will work fine; he should try it and see. There are several things that do not make sense here so let's look at them:

Mercury's Flo-Torq application chart is ambiguous. For starters they do not list Tony's motor at all. My experience is that Mercury and Yamaha motors will take the same props which is what Dick is suggesting.

Flo-Torq hub kit #835257K 1 *is* for MerCruisers but it is also for virtually all Mercury Outboards from 60 hp and up. I have a copy of the Flo-Torq application chart that I printed a couple months ago and it confirms this.

However, looking at the chart online this morning I see they have now substituted part number 835257Q 1 (what Dick has cited) for the 60 hp and up Mercury Outboards while maintaining 835257K 1 for the MerCruisers.

The weird thing is that these kits are (apparently) the same. A Flo-Torq hub kit is a collection of different parts. What distinguishes one kit from another may only be one of these parts. Examining the list of parts for both kits I can discern no difference whatsoever.

The one difference between this kit and what Tony will need is the nut. Mercury and MerCruisers use a notched spacer/washer that engages a tab washer. Yamaha (and most other manufacturers) use a notched nut and a cotter pin. I think Tony can simply use the nut he has and a new cotter pin and he will be good to go.

elaelap posted 12-31-2005 10:40 AM ET (US)     Profile for elaelap  Send Email to elaelap     
Continued thanks, all. This is new to me, and my local Yamaha dealership (with the mechanic I've trusted with two motors and my life for almost 1100 hours/3+ years) is closed 'til January 3rd, so it looks like I'll just have to experiment when and if the weather ever breaks out here. I'm actually thinking about giving up on Whalers altogether, selling my OR 18 through the Marketplace forum, and building an ark. I'd do it for sure, but I don't think it would do much good since I well remember the Good Lord's warning: 'No more water...the fire next time.'

Happy New Year, you Whalers. We're about to turn the corner on this weird, often disasterous year. Best luck to all of us in the coming one, and keep looking for that rainbow sign*.


* "God gave Noah the rainbow sign,
Said 'No more water,
The fire next time.'"
--African-American spiritual, circa 1850

Dick posted 12-31-2005 12:51 PM ET (US)     Profile for Dick  Send Email to Dick     
The thing is confusing and I was surprised that Yamaha required a different hub, I thought it had the same splines as a Merc.
elaelap posted 12-31-2005 05:33 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Well, I just got out during a lull in the storm(s) and everything seemed to go together pretty painlessly:

The splines (if that's what they're called), are in perfect register with the drive shaft, the nut and lock washer fit right, so I think it's a go with this hub kit. Naturally I don't have a torque wrench so I sorta estimated how tight the nut should be. The manual calls for 55 lbs of torque. I think one way of gaugeing whether I got it tight enough is the distance between the after part of the drive shaft housing and the forward portion of the prop itself. As you can see in the photo, I've got them just about exactly lined this correct, or should the forward portion of the prop tuck some into the drive shaft housing? Continued thanks for everyone's help.


(I'm stoked.)

elaelap posted 12-31-2005 07:05 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Last question answered via telephone from Tom Clark...thanks! I removed the prop and, using a block of wood, drove the composite drive sleeve further down into the prop, allowing the forward part of the prop to directly engage the forward brass drive thrust washer, et voila. The nut and lock washer neatly snugged down and the forward portion of the prop is now tucked maybe 3/8-7/16" inside the drive shaft housing, leaving about that same amount of threaded drive shaft showing out past the nut.

Thanks again, guys. Now for some decent weather so I can test this thing.


Tom W Clark posted 01-01-2006 11:10 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
This exercise with Tony pointed something out to me that I had not thought of before but is now obvious. There is no reason at all one cannot use the Mercury tab washer in lieu of the cotter pin on a Yamaha motors.

In Tony's case he used everything that came with his Mercury hub kit and it all fit perfectly.

He could have bought a hub kit for his Yamaha that would have come with a notched nut and cotter pin (or reused what he had) but there is no advantage to doing so.

jimh posted 01-01-2006 02:32 PM ET (US)     Profile for jimh  Send Email to jimh     
Here is another discussion on the nomenclature Mercury uses with their Flo-Torq hubs. It seems somewhat complicated:

LHG posted 01-04-2006 06:03 PM ET (US)     Profile for LHG    
Way before Flo Torque II, saavy Yamaha owners (like Backlash here) have been able to run Mercury props on their engines. The reason for this, is that the Yamaha gearcase and prop shaft design was "borrowed" from Mercury, just as their original powerheads were "borrowed" from OMC.

It is not necessary to purchase a Yamaha specific hub kit to install this prop. In the parts listing, the only thing that is different is the addition of a "space washer" #12-850076 (whatever that is!) and the Mercury tab washer and locknut are deleted. I assume the original Yamaha nut and cotter pin are still used.

But Tony must be warned. As it has turned out, so many Yamaha owners have switched to Mercury props over the last 20 years, that the company has now decided they must take action to prevent this loss of propeller marketshare. It is widely rummored that any Yamaha manufactured within the last 3 years now contains a new ECM which is programmed to cause a blown cylinder if the engine is operated for more than 10 hours with a Mercury prop. I understand the 250 and 300 HPDI's were the first line of engines fitted with this ECM, and it has proven so successful, that all 4-strokes are now incorporating this anti-Mercury prop feature.

elaelap posted 01-04-2006 06:55 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Ah-ha, Larry. Now I know why you were so helpful five or six months ago when I first started talking about changing props.

Ten hours, eh, and then watch out? Well, the weather has finally broken out here and looks like it's gonna be nice tomorrow, so I've told my secretary and our receptionist about the sudden onset of a cold. I've heard that fresh air and sunshine is good for this kind of malady, so I'll be heading out to Bodega Bay tomorrow to cure my ills. The swells are still large and the seas gnarly so I'll probably stay in the harbor. I'll make sure the treatment lasts less than ten hours...wouldn't want to blow up my motor. I'll report on results.


Backlash posted 01-05-2006 10:19 AM ET (US)     Profile for Backlash  Send Email to Backlash     
The Flo-Torq II hub kit (Part #835271Q2) for Yamaha outboards, mentioned by Dick and Tom, contains a Yamaha-specific thrust washer, Part #12-853948, as well as a spacer washer, Part #12-850076, Larry mentions.

My used Mercury Offshore prop came with the Mercury hub kit and (using the Mercury thrust washer) the leading edge of the prop was not inside the lower unit housing. I bought the Yamaha thrust washer and spacer washer and the problem was solved. BTW, the Yamaha spacer washer is only necessary if want to use the Yamaha notched nut and cotter pin, otherwise the nut threads past the cotter pin hole in the prop shaft.

As Tony has pointed out, it is absolutely critical that the composite drive sleeve is firmly seated in the prop hub. This insures that the leading edge of the prop is just inside the lower unit housing.

Tony, good luck with the prop!


elaelap posted 01-05-2006 11:14 AM ET (US)     Profile for elaelap  Send Email to elaelap     
Thanks Steve and others. I'm heading out right now, not to Bodega Bay because the roads heading out there are still raggedy and torn up from the flood, but up to nearby Lake Sonoma. I'll report later on the results of the prop change.
outragesteve posted 01-05-2006 01:19 PM ET (US)     Profile for outragesteve  Send Email to outragesteve     
I just ordered Merc Trophy+ props for my 22'/twin F100 Yammies, 13 3/4x17 w/ Torq II kits. I was not sure which kit would work, so I ordered the only 2 that might fit: Merc #'s 835272Q1 & 835271Q2. The current props are stock aluminum 15" pitch, and I can turn them 6200 RPM @ 38 MPH: Not bad for 200 HP on a 22! Hopefully my RPM will come down 200-400 and maybe speed will pick up slighly. I will post all the results after I test. Also going to raise the engines, after both prop test, 1 and maybe 2 holes, to see what happens. Good luck with your new prop.
Tom W Clark posted 01-05-2006 02:53 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

The Trophy Plus is an odd choice for your boat. Those props are mostly intended for Bass and Flats boats that run their motors at very high elevations.

Having said that, what you want for a hub kit is really 835257K 6 which *might* necessitate the substitution of the #853555 thrust washer.

Otherwise use the 835272Q 1 hub kit but also use the added bushing #8561630 1 which is used for extra support with the highly raked Rev 4, Tempest Plus and Trophy Plus props.

LHG posted 01-05-2006 03:47 PM ET (US)     Profile for LHG    
OutrageSteve - Like, Tom, I would be hesitant in recommending the Trophy Plus for twin installation on an offshore boat. Those props are meant for single engine rigs that can do 50 MPH or higher and need a high engine height to perform properly. On an offshore hull, especially in twin mounting, such engine height is generally not recommended. They are agressively pitched and I wonder if the F100/90 can turn them up high enough.

On my twin 115 HP powered 18 Outrage, which can do 60 MPH, I tried a pair of these in 24" pitch and found them not easy to use. The engines could only turn them up to 4500 RPM much to my surprise. I ended up selling them, and switched to Laser II's which are ideal in twin installations. Your problem, you don't have enough speed or power to turn the minimum 20" Laser II pitch offering.

I would STRONGLY recommend you go to the prop selector program, and plug in your mumbers using the Merc 90 4-stroke, your identical engine. I'm guessing it will give you 16" Vengeance props. These should greatly improve your performance over the aluminums you are currently running. Another alternative would be the Michigan Wheel Rapture or Stilleto, in 17" pitch. On a twin engine 22, I would think your engines should be in the 2nd set of mounting holes, as recommended by BW.

Finally, get in touch with BigJohn here, who is also running this Trophy prop on his 170 Montauk, in offshore conditions

elaelap posted 01-05-2006 05:03 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Here are the results, such as they are, of a comparison between a stock (for two stroke 115) Yamaha black stainless 19" prop and an 18" pitch polished stainless Mercury Vengeance prop on a 2004 Yamaha 115 hp four stroke EFI mounted on a 1988 Outrage 18, 8 hp Yamaha two stroke kicker + 4-5 gallons of premix in a tank on/in the transom portside, two batteries in the console, 70-80 lbs of salmon weights in the cooler seat in a bucket on the starboard side, full (60+ gallons) tank of gas, no bottom paint, single 200 lb person (me) on board. Test was held on flat calm 1000 ft elevation fresh water lake, water temperature approximately 58 degrees, similar air temperature.

Because of recent flooding, the lake has risen high enough to completely flood--to the roof top--the private marina bait shop, and substantial debris including large semi-submerged logs and tree limbs were everywhere, so the speed runs were fairly short (+/- 1/4 mile), made by backtracking my much slower exploratory wake. By the way, not one other boat was observed on Lake Sonoma (except in slips in the torn-up marina) during my entire two-hour trip...that's certainly odd at any time of the year.

Now for the results: No objective, discernable change at all! My boat, carefully trimmed out and checked via GPS at various motor angles with the new prop, still struggles to reach 5600 turns (I'd like to get closer to 5800+, though the current 55-5600 is within the Yamaha manual's recommended 5500-6000 rpm range), and my speed topped out exactly the same (maybe half a mile per hour faster, which doesn't make any mathematical sense at all) as with my OE 19" prop -- 35.6 kts or a little less than 41 mph (if my math is right). Subjectively (and maybe it's because I haven't been out on the water for several weeks) the boat felt slightly quicker onto plane (she's always been real quick with one or two people aboard...3-4 seconds) and seemed to have a bit more acceleration up through maybe 45-4800 rpm, where the curve began leveling out).

This is somewhat disappointing, since I'd love to keep the shiny, sexy Vengeance prop if I could justify the change, but I'm gonna try a 16" or 17" inch prop and try to boost my turns some. Thanks again for everyone's sound advice (and yes, Peter, the prop DID loosten up a slight bit after that two-hour trial, and would have to be tightened if I were going to keep it); special thanks, of course, to the generous donor (who has still chosen not to reveal his's a hint--Take Care, you Whalers ;-) ). I'll clean the prop up and ship it back this weekend.


Tom W Clark posted 01-05-2006 05:39 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

This is a very interesting result. Same speed from an 18" prop as the OE 19" prop. This tells us that it is running more efficiently with less slip. This would also suggests that because of its lower pitch it *should* be getting you on on plane easier and keeping you there at lower boat speeds, not a bad thing in and of itself.

I agree, the next prop to try would be a 17" Vengeance. Perhaps someone wants to trade their 17" for this 18"?

Whoa! don't ship that thing yet. I don't want it but somebody certainly will. It's just as easy to ship it from CA as it is from WA.

Tom W Clark posted 01-05-2006 05:45 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
So, Yamaha F115 with a 2:15 gear ratio, 5600 @ 41 MPH, the slip numbers appear to be:

7.6 percent with the Mercury Vengeance 18" pitch

12.5 percent with the Yamaha 19" pitch

The Vengeance is doing a much better job.

Peter posted 01-05-2006 06:22 PM ET (US)     Profile for Peter  Send Email to Peter     
Tony -Looks like the same style Yamaha OE steel prop in the 17P size would put you right at 6000 RPM. If I were you, I'd get that Mercury time bomb off your prop shaft ASAP and make sure you run a virus and anti-spyware scanner on your EMM particularly looking for and erasing any Mercury viruses or spyware that it might have become infected with when your motor was in contact with the Mercury propeller! Your Yamaha may never be the same again. ;)

Tom - Your slip comparison assumes that the way Yamaha and Mercury designate/measure their pitch to be the same. My experience is that Mercury tends to measure their pitch relative to OMC and Yamaha propellers differently in that Mercury propeller pitch seems to be understated relative to OMC and Yamaha, or conversely, OMC and Yamaha overstated relative to Mercury. The best way to determine the effectiveness of any propeller is through the use of a fuel flow monitor capable of reading out MPG such as a Navman 3100. Propellers that have excellent computed slip are not necessarily propellers that are the most effective at converting fuel into forward motion.

ratherwhalering posted 01-05-2006 08:13 PM ET (US)     Profile for ratherwhalering  Send Email to ratherwhalering     
Tony, I have one thing to say.

13.25 x 17 Stilletto Advantage I propeller, part number 31317.

outragesteve posted 01-06-2006 01:58 PM ET (US)     Profile for outragesteve  Send Email to outragesteve     
Tom and Larry: Thanks for the info. I realize the Trophy may not be a best or even good choice, but I wanted to try a 4 blade prop just to see. Will let you all know on my sucess (or failure!) thanks
elaelap posted 01-07-2006 03:01 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Here's part of an email I sent this morning to Tom Clark (the generous donor/lender of that Vengeance prop). I think it's important to post this because it's my final opinion about the fit between the Flo-Torq hub kit which came with the prop and my Yamaha motor:


"And you know, there was substantial fore-aft play
(maybe 3/8-1/2 inch) after the test run, and without a spacer on the leading edge of the brass thrust washer I don't know whether the thing would have ever snugged up and seated properly. I just examined the forward thrust washer of my Yamaha prop and it has a 1/4-3/8" spacer/flange cast into its leading (forward) side, so
maybe that particular Flo-Torq hub kit ISN'T the right one for my motor. Maybe I should have switched the forward thrust washers and it would have solved the problem.

That didn't really affect the brief test at all, but it would be troublesome and problematic to use the hub kit with my motor without a [+/-] quarter-ince spacer in front of that Flo-Torq hub kit's thrust washer, so maybe that's what there is in the Yamaha-specific kit, eh?

Anyway, a fascinating experiment which has me enthusiastic to keep trying, and this old dog has learned some new tricks about props, which is a good thing. Thanks again, and hope to see you soon."


jimh posted 01-07-2006 03:10 PM ET (US)     Profile for jimh  Send Email to jimh     
Tom Clark posits about the performance of the Mercury and Yamaha propellers:

"7.6 percent with the Mercury Vengeance 18" pitch

"12.5 percent with the Yamaha 19" pitch

"The Vengeance is doing a much better job."

Actually, it looks like the propellers are doing the identical job, as they both propel the boat to the same speed at equal engine speed. The concept of one being "better" because its rated pitch is lower is somewhat of an artificial result. All Mercury has to do to obtain this advantage is to mark the pitch on their propeller to be lower than the pitch marked on the Yamaha propeller. In fact, this may be the biggest difference between them.

In testing a number of Mercury propellers compared to OMC propellers, my conclusion is that the pitch marked on Mercury propellers tends to be on the low side of actual pitch based on how it performed in a number of tests. This often produces calculated values of SLIP which are very low, sometimes approaching zero or even producing negative numbers.

Tom W Clark posted 01-07-2006 03:12 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

I don't think so. If you needed a spacer in front of the prop, then in the absence of said spacer the prop would have been making contact with the gearcase and would have been a big chewed up mess and this was not the case.

What you are describing a either a need to tighten the nut more (assuming there is enough thread left on the shaft) OR the need for a spacer behind the prop to keep the nut within the threaded portion of the shaft.

Tom W Clark posted 01-07-2006 03:14 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Peter & Jim,

Yes I agree with what you are saying. The proof of the pudding is in the tasting.

elaelap posted 01-07-2006 06:22 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Okay, I've now taken my Yamaha '19 K' prop apart, cleaned everything up, re-lubed, reassembled, and re-mounted my prop; and I'll try to explain what's needed: The forward thrust washer on the Yamaha is different from the one that came with the Mercury Flo-Torq II hub kit (835257K 1) in that it has a 1/4" 'thick' circular protrusion cast or turned in front or forward of the main bearing disc of that thrust washer (I'm obviously making up these names). The 'female' interior of this protrusion is tapered to fit smoothly against the tapered 'male' splineless-with-slightly-greater-diameter portion of the drive shaft inside the drive shaft housing (just forward of where the splines begin). The forward thrust washer of the Flo-Torq II hub kit which came with the Vengeance prop doesn't have this protrusion, nor does the hole through that thrust washer taper at all, so it's not designed to exactly fit the Yamaha tapered drive shaft. Also, on the OE Yamaha hub kit there is a 1/16" washer aft/outside the rear thrust washer which forces the prop further forward when the Yamaha bolt is tightened the proper amount (snugged up enough to allow a cotter pin to go through the hole in the aft end of the drive shaft).

Clear as mud? I guess I better give up on my dream of becoming a technical writer until I at least understand the difference between a nut and a bolt ;-)

My conclusion is sound, I suspect. That particular hub kit is wrong for a 2004 Yamaha 115 four stroke EFI outboard motor.


Tom W Clark posted 01-07-2006 06:41 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

Hub kit #835257K 1 uses thrust washer #835467 1. This thrust washer is tapered on the inside. I know this because it's the same thrust washer I use on my Mercurys. In fact is exactly as you describe the yamaha thrust washer.

This is really weird. I've gotta go take a photo now.

Tom W Clark posted 01-07-2006 06:46 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Here is an image of thrust washer # 835467 1:

It comes with hub kit # 835257K 1 which is what (I think) Tony was using.

Tony, does this look right?

elaelap posted 01-07-2006 07:50 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Yeah, that looks like the one that came with the Vengeance Flo-Torq II hub kit, except the one that came with this kit was brass. On the Yamaha 19 K prop's front thrust washer, on the side you can't see in your photograph, is the protrusion I'm talking about. It looks exactly the same on the side shown in the photo...the side that the prop snugs up against. I could kick myself for not taking a photo, but I'm not taking everything apart again, at least not today ;-)
Tom W Clark posted 01-07-2006 07:58 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

All these thrust washers are brass.

As to the rest, you lost me.

rjgorion posted 01-07-2006 08:23 PM ET (US)     Profile for rjgorion  Send Email to rjgorion     
Larry, et. al.

I have a Yamaha F 150 on my Outrage 18. I recently aquired a Stiletto Advantage II prop 14.25 x 19 (without flo-torque) from one of our own. This prop was for a mercury 150 and after purchasing the appropriate thrust washer and spacer (as discussed above) it installed perfectly on the Yamaha. After ~ 12+ hours of running with this prop all is well and I am very happy with it. However, my question is even with the ECM in the F 150, how does the engine know that it is a prop designed for mercury or are stilettos safe? Even if the Stiletto is safe, how would the engine know what prop is on there. I'm not trying to make a joke or be a smarty, I'm just trying to understand this situation. Thanks in advance,


Tom W Clark posted 01-07-2006 08:25 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

You may not have been "trying to make a joke or be a smarty" but Larry was. You have no worries.

rjgorion posted 01-07-2006 08:28 PM ET (US)     Profile for rjgorion  Send Email to rjgorion     
Thanks Tom.

Backlash posted 01-08-2006 10:12 AM ET (US)     Profile for Backlash  Send Email to Backlash     

Here are some photos of my Yamaha thrust washer which show the protrusion you are referring to:

I assume this is the same thrust washer you have, and if so, is the Yamaha, not the Mercury thrust washer.

Prop wise, I would seriously consider the 4-blade Mercury 17 pitch Offshore/VenSura for your boat.


elaelap posted 01-08-2006 10:59 AM ET (US)     Profile for elaelap  Send Email to elaelap     
Thanks, Steve. I told Tom last night via email that if it wasn't raining today I'd pull my prop again to take some photographs. Now I don't have to ;-) Your photo on the left shows the difference between our Yamaha thrust washers and the kind which came with that particular Flo-Torq II hub kit. The Vengeance/Flo-Torq II t.w. is flat on the forward or leading side shown in the photo on the left; the other or aft side--the side which the propeller seats against--is exactly the same. What doesn't show up clearly in the photographs is the fact that the hole through the Yamaha t.w.'s leading edge is tapered for the first half inch or so, allowing it to exactly fit the tapered drive shaft.

Again, the important bottom line here is that if one is planning on running Mercury props on Yamaha motors it is necessary to get the proper Flo-Torq II hub kit, and this one wasn't it (though it served perfectly well for a brief trial run).


Tom W Clark posted 01-08-2006 11:19 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
OK, I see now that the Yamaha thrust washer is effectivly about 1/16" thicker (because of the added "protrusion".) But I don't see any other difference.

Tony, you keep making a point of saying the Yamaha thrust washer is tapered to match the taper of the propeller shaft, but so is the Mercury thrust washer, or at least #835467 1 is (photo linked to above.)

What am I missing?

Tom W Clark posted 01-08-2006 11:39 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
The Mercury Offshore/Vensura is only for V-6s, not mid range motors like Tony's F115.
elaelap posted 01-08-2006 12:04 PM ET (US)     Profile for elaelap  Send Email to elaelap     
I think that the hole through the t.w. which came with the Vengeance 18P prop--Flo-Torq II hub kit (835257K 1)--was NOT tapered. I remember thinking about this as I slid it down past the drive shaft splines and up against the tapered, larger diameter part of the Yamaha drive shaft and thinking, "Huh?" or "Duh?". Let's see what the new purchaser of the prop reports...he should get the thing tomorrow afternoon.


A little more seriously, it seems to me that the forward thrust washer we're discussing is designed to seat flush against a non-tapering increased diameter portion of a different drive shaft. Sure wish I were better at describing this stuff.

elaelap posted 01-08-2006 12:25 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Here--please don't laugh too loud, Moe and others:

Oh, I guess I better warn you that this sketch is NOT TO SCALE ;-)


LHG posted 01-08-2006 02:25 PM ET (US)     Profile for LHG    
Tony - I, and the world, sure are lucky you decided to become a Lawyer instead of an Architect!
elaelap posted 01-08-2006 02:38 PM ET (US)     Profile for elaelap  Send Email to elaelap     
You got that right, Larry.

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