Long term effects of aftermarket fins

[ajvigants]

I get my 190 FSH next week and already shopping for things to add.

The Thrust Vector and CJ Viper systems are both interesting. In a boat that I will fish from low speed tracking is especially important. In general, I prefer things made of metal to things made of plastic or composites. I also prefer things that have fewer moving parts to those that have many. I appreciate that Thrust Vectors swing up when at speed but it is also true that the rudder on the new boats protects the Vipers. The difference in price is not a deciding factor for me. Both gentlemen have loyal followings.

What holds me back is an abundance of caution, a career as an engineer and having worked for large manufacturers (Emerson, Boeing). Yamaha Boats, as market share leaders, must be some of the highest volume boats in production, right? So more than anyone else, Yamaha probably have the engineering horsepower available to try and squeeze every last penny out of the manufacturing process. That means making components as heavy duty as they need to be, not heavier (as opposed to my old Malibu WakeSetter which is layer after layer of heavy fiberglass - wonderfully solid, but heavy). That applies to the thickness of the fiberglass, how heavy the metal parts are and whether to use sensible brass drain plugs or silly little plastic ones.

What I am getting at is that the steering mechanisms (cables, linkages, castings, etc.) were designed for the stock rudder / steering system. Certainly they made them as light duty as they could get away with without creating a warranty nightmare or staining the brand image. I've seen posts claiming that the extra fins either add no stress or reduce stress, but I question the validity of those claims. The stress/force that a rudder/fin experiences is primarily a function of surface area, angle of attack and velocity (navy white paper on rudder design) so there is little doubt that more surface area means more force. In fact, if there were not more force, the steering would likely get worse, not better.

I assume that at low speeds (when they are most necessary) nothing bad is happening. But for any fin that is deployed at speed, I wonder how far into Yamaha's design engineers' safety margins this is eating? I am not an expert on the complete history of all of the fin designs that have ever been tried - it seems like all of the TV models always deployed only at low speed but some of the CJS fins are always deployed. The new CJS Viper fins are certainly "always on".

I'd like better handling, but not at the cost of wrecking the boat prematurely. So what I am wondering is what the people who have had aftermarket fins for many years (especially those that are deployed at all speeds) have experienced in terms of wear and longevity of the related components?

 

[Julian]

I had Cobra fins on my 2005 SX230 for 10 years with no issues. The only issue I've seen with fins is when you hit something in the water, you add risk that the fins might cause more leverage on the nozzles and bend/break them. But that is the nature of adding something that hangs down lower...

 

[Cobra Jet Steering LLC]

There is something called over engineering or overthinking , I could explain a lot to you since I have been doing this for 15 years but I will just say go buy the boat, leave it stock, if you hit a rock with the stock rudder from the factory you will likely destroy it, I get people telling me this has happened already with the stock boat, if you think Yamaha has infallible engineers go look at the new twin engine rudder setup, and the year 2000 to the year 2016 clean out plugs , while you are at it look into the timing chain issues with the 1800 engines. If you want a boat that will not break down try a canoe. If you want some kick ass steering just ask my customers And I'm not an engineer but steering it's what I do.
And while you are researching Yamaha engineering capabilities take a good look at the NANO hulls on wave runners. and the location of the rudder on your own F S H the look at some of my early patents like 6561858 or 6702630 and see where I placed the rudders.
Aftermarket steering is not new not even close, this is like asking if windshield wipers will eventually wear out the windshield.

 

[scokill]

, this is like asking if windshield wipers will eventually wear out the windshield.

I love it....

 

[ajvigants]

"if you think Yamaha has infallible engineers"

Jeff:

What I am really worried about is precisely that they are not infallible. If they were perfect, I'd expect enough safety margin to be "baked in" so that adding fins would be a non-issue. But if they cut things too tight in pursuit of the almighty dollar, then it could be an issue.

Suggesting that I should "try a canoe" seems like an odd choice of words to direct at a potential customer (already a customer, in fact - you just shipped me an EZLOCK) - but it is hard to convey tone in emails and forum posts.

Anyway, you look at each set of fins as a transaction of a few hundred dollars, while I am trying to decide whether to risk harming my $30,000 boat. So asking questions beyond just accepting forum posts blindly is not, in my opinion, "over engineering or overthinking". In most cases people vigorously defend their own buying decisions (confirmation bias) and frankly, anyone that has just bought them (within say 50 hours of operation) has no useful insight about long term effects. Those are not the people I want to hear from. I am looking to hear from people like Julian with many years of use.

What would be very helpful would be to share a rough approximation of how many CJS units are likely full-time deployed versus how many are deployed only during slow speed operation as well as a rough population size. If all Thrust Vectors and 80% of CJS systems are only being used at low speeds and if some of the remaining boats get used very little, it may be that the population of fins deployed at high speeds on a regular basis is very small . . . small enough that problems are not bubbling to the surface. Yet. Or maybe there is no issue. That is why I am asking.

I am not questioning that you are an expert in creating "kick ass steering" but I do think it is worth asking to see if there is data to support the notion that there is no harm being done. And, just to be clear, by "data" I mean users who have put 50-100+ hours on with fins deployed at high speeds.

You said to, "just ask my customers". That is exactly what I am doing with this thread.

Ultimately I am not only trying to decide whether yes or no to fins, but also TV vs CJS and Viper vs Ultimate, etc..

I am pretty sure that I do want the low speed assist - just not sure if deploying at high speeds is wise.

 

[ajvigants]

I had Cobra fins on my 2005 SX230 for 10 years with no issues. The only issue I've seen with fins is when you hit something in the water, you add risk that the fins might cause more leverage on the nozzles and bend/break them. But that is the nature of adding something that hangs down lower...

Julian: are your fins always deployed (incl at high speed)?

 

[ajvigants]

I love it....

A better analogy might be to look at how many wakeboard towers have made a mess of the boats they were attached to.
It isn't the tower manufacturer's fault that the boat was not built well enough, right?
Not the tower manufacturer's fault that the installer did not put in large enough backing plates, is it?

Sorry, but the windshield wiper analogy is flippant and not productive.

 

[Julian]

Julian: are your fins always deployed (incl at high speed)?

Fins on my SX230 were always deployed.

 

[scokill]

"if you think Yamaha has infallible engineers"

Jeff:

What I am really worried about is precisely that they are not infallible. If they were perfect, I'd expect enough safety margin to be "baked in" so that adding fins would be a non-issue. But if they cut things too tight in pursuit of the almighty dollar, then it could be an issue.

Suggesting that I should "try a canoe" seems like an odd choice of words to direct at a potential customer (already a customer, in fact - you just shipped me an EZLOCK) - but it is hard to convey tone in emails and forum posts.

Anyway, you look at each set of fins as a transaction of a few hundred dollars, while I am trying to decide whether to risk harming my $30,000 boat. So asking questions beyond just accepting forum posts blindly is not, in my opinion, "over engineering or overthinking". In most cases people vigorously defend their own buying decisions (confirmation bias) and frankly, anyone that has just bought them (within say 50 hours of operation) has no useful insight about long term effects. Those are not the people I want to hear from. I am looking to hear from people like Julian with many years of use.

What would be very helpful would be to share a rough approximation of how many CJS units are likely full-time deployed versus how many are deployed only during slow speed operation as well as a rough population size. If all Thrust Vectors and 80% of CJS systems are only being used at low speeds and if some of the remaining boats get used very little, it may be that the population of fins deployed at high speeds on a regular basis is very small . . . small enough that problems are not bubbling to the surface. Yet. Or maybe there is no issue. That is why I am asking.

I am not questioning that you are an expert in creating "kick ass steering" but I do think it is worth asking to see if there is data to support the notion that there is no harm being done. And, just to be clear, by "data" I mean users who have put 50-100+ hours on with fins deployed at high speeds.

You said to, "just ask my customers". That is exactly what I am doing with this thread.

Ultimately I am not only trying to decide whether yes or no to fins, but also TV vs CJS and Viper vs Ultimate, etc..

I am pretty sure that I do want the low speed assist - just not sure if deploying at high speeds is wise.

I don't have fins because they are unnecessary for us,

A better analogy might be to look at how many wakeboard towers have made a mess of the boats they were attached to.
It isn't the tower manufacturer's fault that the boat was not built well enough, right?
Not the tower manufacturer's fault that the installer did not put in large enough backing plates, is it?

Sorry, but the windshield wiper analogy is flippant and not productive.

Not trying to be a jerk, so would appreciate the same courtesy on your 15th post or so.

There are many folks on the forum and other Yamaha specific forums that have either installed Cobras or TV, or seen posts of thousands of folks that have installed and used. This includes the Cobras that didn't flip up at all and were engaged down at all times, to the new model that gives you a lot of flexibility to customize your steering assist, and to my recollection the only damage I've ever seen is when somebody hits something.

Let's say for a moment there was even a remote risk that the nozzle would wear over time....would you buy a new boat for $30,000 because the nozzle was damaged? No, you would replace it for a couple of hundred bucks. There are many more things that have a much greater likelihood of happening with way more risk, but you are doing your due diligence and fair enough, but you will get a variety of comments so it comes with the territory. Take the wealth of information here and lighten up.

 

[Cobra Jet Steering LLC]

You have the cart before the horse. I think you should take some time to research things like fangs and how they work , perhaps that would have ended your quagmire right then and there.
But I have found that after 9000plus Yamaha jet boats adding one form or another of my steering systems to the jet nozzles that provide a wide variety of assistance from slow speed to all time assistance and anywhere in between and considering the fact that people usually modify the boat to fix issues not just in anticipation to issues, as some will say you don't need any extra steering. Certainly not even the rudder that the factory installed in the lowest point of the boat behind a keel because it was the only way they could do it to work around existing patents.
Just look in public par at the patent office I believe the number for their patent attempt is 13678860 it certainly was not in my opinion the best way to do it but perhaps the only way as an engineer you should understand how that works .
Since you have no time in the boat you have no idea what if anything you need to do to make it comfortable for your style of boating. So do your homework, look at the parts offered what they do and how they do it, then get some first hand experience in the boat and decide what if anything you need to do , as for wearing out the nozzles well those various systems can actually deliver more or less work load, yes less if you use the fangs. Just look at the videos I posted about sub moves and imagine the huge stress placed on the nozzles with no ill effect and then realize just how obvious the answer to your question is and then go figure out why Yamaha built a one legged steering system behind a huge keel with a rack and pinion system that requires twice the travel to move the rudder and works it off just one nozzle and steering cable.
Perhaps if you had come here asking as a novice jet boat owner I would have had a different answer but posting that you are an engineer holds you to a higher standards with less room for questions that indicate you probably did not do your research before you posted this thread. I believe Takata has some openings.

 

[swatski]

A better analogy might be to look at how many wakeboard towers have made a mess of the boats they were attached to.
It isn't the tower manufacturer's fault that the boat was not built well enough, right?
Not the tower manufacturer's fault that the installer did not put in large enough backing plates, is it?

Sorry, but the windshield wiper analogy is flippant and not productive.

I'm sure you are aware that:

1. If you want to add power steering at speed (any speed above "no wake") the Cobras are designed to do that. I believe those come with a warranty (if you don't like the function or how those work).
2. The Vipers have become available only recently so there can not be any long term reviews. (???).

In your poll questionnaire, are you concerned with "wear" or "premature wear"? If the latter, my answer would be "no" concerns - I have seen no posted evidence of "the added stress of aftermarket fins damage the boat over time". But based on your responses here, I think you're asking about wear in general and in that case I think the windshield wiper analogy is most appropriate. And here is another one: will driving a car eventually ruin the tire threads?

If you keep your boat long enough you will need to replace steering cables at some point, I'm not aware of any evidence that fins shorten cables' lifespan. If anything the FANGS or the Vipers should reduce the stress on steering nozzles because of their "protrude-forward" design.

Please don't get me wrong, I LOVE well designed polls, comparative testing, and results/data discussion in open forums like this one, as it can be very helpful in purchasing decisions especially for newer customers. But reading your first post it seems you have already answered your own questions.


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[MrMoose]

@ajvigants, I think that your question is a reasonable one. Unfortunately, you won't get a statistically valid answer from any forum. I find that a high percentage of forum participants prefer to keep their cards close to their chest when they have problems that have been sorted out without requiring guidance from forum members, or maybe they just can't be bothered to share their experiences. I'm not criticizing, it's just the way it is. If you're looking for help and advice on how to fix or improve something, you'll find it in abundance on this forum, but if you're asking folks to share their issues, they may not.
Case in point is that when I first started chirping about the problems with my Shoreland'r trailer, only a handful joined in and shared that they too were experiencing issues. BUT, once I shared that Carlisle sent me new tires, well then folks started coming out of the woodwork and posted when they also got new tires, and I'd bet that there are still lots who got the new tires, but couldn't be bothered to post about it.
So, you'll get opinions, but in the end, you'll have to go with your gut.
Although my 2015 has the articulating keel, steering without thrust is almost non-existent. ... So, I just give a little thrust and have no issues with handling at low speeds as the boat tracks quite well. Would fins improve the situation? Sure.
A while back, I seem to remember reading posts about broken steering cables, and it was my impression that those who shared their broken cable stories had fins installed. I believe that I read a post from someone who was suggesting that the fins caused his cable to break. I'm not saying that the steering cables were not defective or old to start with, nor that the fins caused them to fail. I'm just pointing out that there is a possibility that the additional stress that fins put on the cables could contribute to cable failure. I honestly don't want to hear any comments about "power steering". I assume that there is a reason that airplane rudders do not have pivot points that enable "power steering".
It's the possibility of these additional stresses causing premature steering cable failure that made me to decide to leave my boat stock. That's what my gut told me to do. I also believe that there has been discussion that the fact that the new articulating keel is controlled by a tie rod connected to the starboard nozzle could be causing premature wear on the starboard steering cable. This made me consider adding a second tie rod to connect the keel to the port nozzle to distribute the stress between the starboard and port steering cables. I decided not to do this because I didn't want any additional binding stresses added to my port steering cable by tying it to the starboard side. If I was really worried about premature wear on the starboard cable caused by the stresses from the tie rod, I'd just alternate the tie rod from side to side after each season.
I called Yamaha about all of this and their answer was simple. "We have not tested these modifications, and as such we do not recommend that you do them."
So, moving forward, I'm still tempted to have a second tie rod available on board to link things up if one of my steering cables fails. This would give me full steering control in order to get back to port, or to finish up a vacation.

In the end, you'll have to go with your gut.
Don't hesitate to share your final decision.

 

[Cobra Jet Steering LLC]

Really airplanes and boats ??? air is compressible and water is not, boats travel a lot slower than airplanes let me help you understand power steering on a boat it has been around for a long time

0h and if you take a look at the front of the rudder on the 19 foot boats, Yamaha added an extension to their rudder that also works similarly, I thought you told me you were an engineer???

 

[swatski]

I find that a high percentage of forum participants prefer to keep their cards close to their chest when they have problems that have been sorted out without requiring guidance from forum members, or maybe they just can't be bothered to share their experiences. I'm not criticizing, it's just the way it is. If you're looking for help and advice on how to fix or improve something, you'll find it in abundance on this forum, but if you're asking folks to share their issues, they may not.
Case in point is that when I first started chirping about the problems with my Shoreland'r trailer, only a handful joined in and shared that they too were experiencing issues. BUT, once I shared that Carlisle sent me new tires, well then folks started coming out of the woodwork and posted when they also got new tires, and I'd bet that there are still lots who got the new tires, but couldn't be bothered to post about it.

@MrMoose here is a case in point for you - or two cases for that matter - two long threads regarding those new Shorland'r trailers' issues started by @subysti and @Glen at least a year before @Majorsmackdown report on his trailer failure on the way back from Bimini and the other two, kindly started by yourself to illuminate the issues further. I'm not sure members of this forum can be accused of shying away from venting about issues with their Yamahas. Re: broken cables - plenty of broken cables' reports and repairs - in boats both with and without fins. And I agree, you won't get a statistically valid answer from any forum - but not necessarily due to participants preferring to keep their cards close to their chest when they have problems. I know I don't!

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[itsdgm]

@ajvigants ive had fins on my 21' boat almost since I've owned it back in 2008. So far, I love what the fins do for me in the way of a more positive steering response. Also, it makes the first time jet boat operator (the friends that I drag to the lake to pull me on the wakeboard) much better at handling the boat right from the start. Which in turn means more wakeboarding time for me

I'm sure the newer fins are probably much better than mine. But I'm happy with how the boat handles, so Ive left it as is. So far, nothing's broken on the boat as a result of the fins. Good luck with your search for the right solution for your situation.

 

[ajvigants]

But reading your first post it seems you have already answered your own questions.--

Not really. I think there is no doubt that the fins introduce different stresses. It also seems reasonable that at low speeds they will be minor and at higher speeds greater. I made no prejudgement of whether this will be damaging. I just don't know. Unfortunately nothing I have seen from the forum (I've read ALL the relevant posts and watched the videos) suggests that anyone else really knows. Saying that a lot of people have used fins is not data. Jeff saying "trust me, I am an expert" is not data. And Mr.Moose is right that people sometimes do not share their problems, especially if they think that they might be self induced in some way (so if I buy fins and the boat is damaged, I'll never breath a word - especially not after starting this thread! Now I absolutely must make the right decision!)

I read the broken steering cable posts with interest but it seemed only to be applicable to twin engine boats - my guess is that the components are shared and what is more than adequate for the 190 series is marginal for the larger boats. Or maybe it was a bad batch. If I had a twin then yes, I'd be concerned. It would be interesting to know how correlated to fin use those cable and rod issues were.

Jeff was spot on with his suggestion that I ask his customers. That is what I am doing. If thousands have used them over a period of many years with no ill effects then I expect that we'll hear from some of them. So far Julian has chimed in, so we have one relevant data point (and a reassuring one at that). I plan to run the boat stock for a few weeks and then I will lose the boat for a week or so while having a T-Top made, so I have some time to watch this for more responses.

It will be interesting.

 

[swatski]

I read the broken steering cable posts with interest but it seemed only to be applicable to twin engine boats

The singles were not sold until late 2012, which is a more likely explanation for the paucity of broken/worn out cable reports of 190s. There is also A LOT fewer of those running around as compared to all the 230s, 210s, and 240s.

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[MrMoose]

@Cobra Jet Steering LLC, I assume that you know that there are different kinds of engineers, and that you don't know what kind of engineering degree I have, so I have to assume that you're just being a dick with the engineer comment.
I kind of want to say something ignorant and sarcastic, but I'm all out of sarcasm and ignorance as I used it all up earlier this week in my other posts.
Yes, I have a masters degree in engineering. I spent many years in quality engineering at IBM. I worked with designers, manufacturing, suppliers, and field techs to qualify designs before going into full production. Access to field failure data is vital to being able to do the job. On this forum, we don't have access to the data, so we're just sharing opinions. If a design change could induce a risk of failure, I would perform tests to investigate the concern before putting the design change into the field, and I would watch field failure data to see if the particular failure of concern was occurring in the field.
I'm not a marine engineer, nor do I have direct experience in hydrodynamics, but I noticed that your examples show the balanced rudder trailing a keel, not a leading edge as they are in your application. Just an observation.

 

[Cobra Jet Steering LLC]

now take a look at this picture of the rudder that is on your new boat it is operated by the nozzle and the cable. the arrow has nothing to do with the rudder it was just on the picture I borrowed now look at the lower portion of the rudder that extends forward of the pivot point. Yamaha has a rudder in the water operating all the time and they have a form of a power steering fixture added to reduce the stress level caused by the rudder.

 

[ajvigants]

@ajvigants ive had fins on my 21' boat almost since I've owned it back in 2008. So far, I love what the fins do for me in the way of a more positive steering response. Also, it makes the first time jet boat operator (the friends that I drag to the lake to pull me on the wakeboard) much better at handling the boat right from the start. Which in turn means more wakeboarding time for me I'm sure the newer fins are probably much better than mine. But I'm happy with how the boat handles, so Ive left it as is. So far, nothing's broken on the boat as a result of the fins. Good luck with your search for the right solution for your situation.

Thanks for chiming in, Dennis. Another positive experience. I see in your signature that you have Cobra fins - do you keep them deployed at speed or just when going slow?