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850 gone down already??

While I appreciate your humor here, I simply see this thread as several people sharing perspectives, ideas and theories on this topic. Does it mean I'm right? Nope...it would take months, if not years, of design, testing and refinement to know for sure. I'm all theory here based on my background. But add a guy like Dan, and others with years of real-world knowledge (which I value much more than theory) and you have some great discussions which tend to support each other. And one thing I have always seen constant is that real-world knowledge/experience always translates back to sound engineering principles/theory. However, engineering theory/principles don't always translate to the real-world application (ever watch the show "engineering disasters"?). Lastly, the cost of quality for mass production is real. Maybe this configuration works great if assembled correctly...but allowing variability to occur by an operator/assembler is a poor approach. One should design-out the chance for variation, and this doesn't have to be expensive...it is cheaper if done correctly. Does this whole issue sound cheap? What is the ROI for moving bearings vs ring located vs failure rates? I sure don't know, but sounds like you might based on your comments?

That said, sitting back and saying people are wrong with no rational or information to back that up is empty and not constructive. The number of times that approach has accomplished anything in the history of the world is still zero. If we are wrong, share your thoughts why? I would like to hear why I may be wrong and learn. I'm passionate about having an open mind and learning...and my ego is not my priority here...not anyone's on here from what I can see.

Where did I say you or anyone else was wrong? Because if you took it that way it absolutely isn’t what I meant? I shared my opinions on the matter if you read back through the thread. To summarize, just because there is a better way (in one aspect of “better”), does not for a second mean it is “better” in the entire scope of the situation for the outcome that is desired. Dans approach is absolutely “better” from a long term durability standpoint, but it obviously isn’t “better” for for volumes, margins, profitability, the 90% of the market they go after, etc when all things are considered...otherwise he’d have have 3 manufacturers buying their engines from him to put in their sleds. People with vast experiences in a technical aspect can get blinders to that part of the equation. Engineers do it, Finance people do it, Sales guys do it, service personnel do it, everyone does it. They really do have the best answer for the portion of the business they represent. What makes Polaris (and many other companies) a $5B dollar company is not because they are perfect at any one thing, but they have been good at balancing all the needs and building products that have the right cost structure for the vast market they are going after. This has allowed the right margins and volumes to grow and succeed. You will ALWAYS be able to find ways to do things better than a major manufacturer...but all things considered, there are typically only a handful of things that, if done differently, would provide a more positive outcome in total. And that’s largely due to the hindsight 20/20 rule... Then there are absolutely those issues that were unforeseen because they thought a certain design would do “X” and it did “Y”.
 
I don’t get why some people get so butt hurt about guys offering their opinion or advice. Some of these guys are obviously very experienced and very educated. I enjoy learning from folks that are a lot more knowledgeable than myself and I’m glad they are willing to take the time to share on here.
And there is at least 10 or more of these guys that together could probably engineer and build a sled as good or better and with less issues then certain $5-6B companies.
Especially if they had all the resources of certain 5-6B companies!

Oh I’m definitely not butt hurt, just offering my perspective and opinion.
 
There a 4.1 billion dollar company btw....lol stock went from 97.00 to 72.00 a share after this thread started......JK but its the same time frame :face-icon-small-dis
https://charting.nasdaq.com/ext/charts.dll?2-1-14-0-0-512-03NA000000pii-&SF:4|5-HT=350-

Lol. Crazy all the investors reading this thread ?

I’ll clarify that I talk Gross Revenue not Market Cap when referencing the size of a company. Gross revenue isn’t impacted on a daily basis based on the rumblings of a President and the twist the media puts on it
 
Wow
Rollers bearings thats caged that uses crank as race has been used for years and years. Cats lay down motors, plus millions more. The tolerance matters for crush and bearing doesn’t move because of crush height
The problem was lubrication to the bearing on a few and tolerances
 
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Great explanation

Let's try to keep things in perspective here.

Almost anything and everything that comes from a corporate mass production assembly line can be improved. No snowmobile manufacturer designs and builds for reliability and longevity. The costs and weight penalties are too high. Especially when recent sales of sleds have fallen for the past 10 years.

They build for performance and the lowest costs possible. I believe they also build a sled with the idea the owner will sell in a max of 2-3 years and buy a new one. We may not like this, but if you think you are mechanically and electrically inclined, dig real deep in your sled and look closely at how it's built and designed.

Companies like Dan work to improve the OEM longevity with the least financial penalty possible. He has to overbuild as much as allowable for him to stay in business and do what he thinks is the best quality job. Small shops (think auto repair also) are not insulated from irate customers like Polaris and other Corporate OEM's are when their machine or automobile breaks down. Especially when it may be premature. They have dealers to take the heat for them. Shops like Dan often have face to face or mouth to mouth contact with their customers. This brings a different element and business model for Dan and other small shops than it does for PI, BRP, etc. When were you able to yell at the CEO of Polaris for your piston skirt blowing through the bottom of your case? You can with Dan.


It can be a real difficult situation for both customer and shop when the shops work comes back. Comeback's or warranty claims have a much bigger impact for a small shop and can be financially disastrous if they get to be too much. So of course shops like Dan will do everything they can to improve on the OE's design to make sure their work doesn't comeback. Something that may work for Polaris' bottom line may not necessarily work for Dan's bottom line.


As for Polaris' test motors working for thousands of miles and time without issues, these motors are delicately assembled by The Real Engineers (thank you to this group) to absolute perfection, much like Dan's motors are. Things often change when you get to the Production line and those Engineers might not like it or agree with it. Assembly line workers are not Engineers and not mechanics. They are being directed to build those motors as fast as possible with work instructions. This is often when decisions are made by senior leadership to be as fast as possible and to cut costs as much as possible. This is often where risk is taken that might lead to premature failures. Shareholders demand returns on their investment.

This is puts everything in the right perspective, great explanation of where everybody fits in the grand scheme of things THANK YOU!!!!
 
No there is clearly a design or manufacturing "whoops" with some of these 850's on the PTO bearing. I am not intimately familiar with the design or assembly. All I'm saying is that an interference fit assembly with dissimilar materials works perfectly fine when properly executed.

Agreed, one more thing that needs to be added to the equation: harmonics
 
Agreed, one more thing that needs to be added to the equation: harmonics


Harmonics is one of those things that is difficult to predict. Rotax used additional weight and even a fluid balancer on the mag side of many of their twin sled and aero engines. This became obsolete with the ETEC having a heavier magneto flywheel for the 1200W stator.

+ Clutch Heat

Whether it is a Cat, Doo or Poo, can't be running 300F belts and expect things to go well. Off-Trail sleds need more cooling and better clutching, gearing and alignment when ridden hard. With stock clutching and misaligned CVT I can easily raise belt temp on any trail sled well above 200F or until the belt delaminates. When I go off-trail it gets hot faster. The PTO bearing(s) doesn't fair well when it gets too hot. I have seen a pto bearing become loose in the case and hammer the bore in the direction of the secondary - granted not an 850.
 
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This is a great thread into the many intricacies of the modern 2 stroke sled motor.

I've pretty much cut through the WHOLE thread...that took a while....

I'm surprised they wouldn't "locate" that PTO roller bearing outer race in the housing. You could use a dowel pin or retaining ring as there isn't much/no lateral load... but vibration, and as mentioned...assembly variations.... can do weird things..

I do like the idea of a big roller and using the crankshaft as inner race. Nothing new...but lighter and less rotating mass. Two thumbs up.

The whole Nikosil (or Nickel Silicone) finishing did surprise me. Having seen many many over the years I always wondered how they finished it. The coating is basically the same as the "Carbide" tools we use to cut steel with so you can appreciate what Dan is saying. A rough finish is going to destroy your dainty single ring in short order even with lube. All you can hope is that your motor was made later in the run when the edge was removed from the diamond honing tools.

I am also concerned with the heat being passed from clutch to crank, but if you consider the etec 850 in the Summit has been reliable with 300F clutch temps....not too worried.

Merry Christmas All!!

OTM
 
Coming from many years in the product development world, albeit in chemicals, I have always appreciated real world feedback while many of my counterparts get defensive. On the bearing issue, I think it was Jim that said it best. In a mass production setting, engineers should design the variability of assembly out of the product. So many engineers are so arrogant and when their baby turns ugly, they blame the next person down the line. In a perfect assembly, is the design sufficient? Maybe. But you need to remember, that assembler isn’t receiving the engineer’s salary. Is a locating measure needed? Maybe, maybe not. But I can say that without a doubt, a locating ring/pin would at a minimum put the bearing in the right place in 100% of the assemblies.

I laugh when people say that they’re a $4-5B company so they must know what they’re doing. To put in perspective, the company I work for is a $15B company and I can attest, we are not always the best at designing and it usually shows it’s ugly head between field test and production where the difference is only who does the production. At which point the engineer starts blaming everybody else and points to all his data he/she had generated to that point. When I formulate a product, I own that product and all plant support/quality for two years. When there’s a problem, I get the call. When something happens in the field, I have to talk directly to the customer so you can bet I formulate with production variables in mind. I also understand cost/benefit. I can guaranty that a locating item would’ve easily passed the accounting sniff test if the engineer was smart enough to include assembly labor in their pitch for the benefits. As a side note, I do get a kick out watching our engineers work on our equipment in the field. Turns out the setting isn’t as clean and you’re usually standing on your head doing it. They get so used to working in a lab setting so it is amusing.
 
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Where did I say you or anyone else was wrong?*

My bad...Im a very sensitive person. I, and everyone else, misunderstood your cynicism and sarcasm towards our comments, while also touting the correctness of Polaris as being obviously correct because they are a 5B company, as saying we were wrong.

Something I think we can all agree on: You weren't positive, backing up or complimenting anyone in this thread.
 
+ Clutch Heat

Whether it is a Cat, Doo or Poo, can't be running 300F belts and expect things to go well. Off-Trail sleds need more cooling and better clutching, gearing and alignment when ridden hard. With stock clutching and misaligned CVT I can easily raise belt temp on any trail sled well above 200F or until the belt delaminates. When I go off-trail it gets hot faster. The PTO bearing(s) doesn't fair well when it gets too hot. I have seen a pto bearing become loose in the case and hammer the bore in the direction of the secondary.

Yes sir, agree. Witnessed it many times also.
Wonder why Fuji always used a locating pin. Hmm
 
My bad...Im a very sensitive person. I, and everyone else, misunderstood your cynicism and sarcasm towards our comments, while also touting the correctness of Polaris as being obviously correct because they are a 5B company, as saying we were wrong.

Something I think we can all agree on: You weren't positive, backing up or complimenting anyone in this thread.

Go read all my posts in this thread. And then have a Merry Christmas.

1. Polaris is not perfect
2. They will not design the best possible design
3. Others will have more experience and better ideas than they will
4. People will find solutions to “issues” and build small businesses out of them where they will provide a solution to a small segment of the market
5. Business are built with people and not all those people agree on the path the leaders take it.

However,

To grow to $1B, $5B, or $15B... they are doing something right or the right mix of things or they would not be alive today. Nobody will ever say they couldn’t be bigger, provide better support, engineer things better, make more money, provide better customer support, or whatever other measurement you want to tout.

Polaris has been building **** engines for long enough for Dan to have built a very successful business fixing them for people. But yet, they continue to grow. Evidently Polaris understands the market they are selling to and that market is willling to buy a crappy product, spend a bunch of money to fix it, and then come back year after year and buy more **** from them.
 
This is the true statement that just boggles my mind....


"Polaris has been building **** engines for long enough for Dan to have built a very successful business fixing them for people. But yet, they continue to grow. Evidently Polaris understands the market they are selling to and that market is willling to buy a crappy product, spend a bunch of money to fix it, and then come back year after year and buy more **** from them. "


I personally bailed on them when I found out I couldn't get two reliable seasons out of a $12,000 machine. Not sure who finds that acceptable and keeps sending them money but it isn't a model that works for me.


Then all of the defenders of the brand.... seriously? They have screwed so many people so many times I honestly do not know how they stay in business at all. The 900 and 800 dragon should be lessons but many of those buyers are back for more defending the next big bomb from Polaris. Good Luck to you but you will likely get what you deserve for not paying attention to past performance. <!-- / message -->
 
This is the true statement that just boggles my mind....


"Polaris has been building **** engines for long enough for Dan to have built a very successful business fixing them for people. But yet, they continue to grow. Evidently Polaris understands the market they are selling to and that market is willling to buy a crappy product, spend a bunch of money to fix it, and then come back year after year and buy more **** from them. "


I personally bailed on them when I found out I couldn't get two reliable seasons out of a $12,000 machine. Not sure who finds that acceptable and keeps sending them money but it isn't a model that works for me.


Then all of the defenders of the brand.... seriously? They have screwed so many people so many times I honestly do not know how they stay in business at all. The 900 and 800 dragon should be lessons but many of those buyers are back for more defending the next big bomb from Polaris. Good Luck to you but you will likely get what you deserve for not paying attention to past performance. <!-- / message -->

Many or most of us ride Polaris because we have not ridden another brand that we enjoy as much. Plain and simple, we are willing to pay to play. If there were another brand I liked to ride as much as a Poo, I would be on it.
 
Many or most of us ride Polaris because we have not ridden another brand that we enjoy as much. Plain and simple, we are willing to pay to play. If there were another brand I liked to ride as much as a Poo, I would be on it.

I have not ridden the alpha but for my riding I chose Polaris fits me the best I will live with issues. Because I don't have time to hand build one.
 
Isn't the holding power for the outer race coming from bolting the cases together? If the interference fit is the same than the holding power will be the same. Only the 850 bearing isn't tied to crankshaft side play so it should be less likely to move.

I understand that having an inner race with a spherical bearing naturally keeps the outer in line but it also applies the crankshaft side play to the outer race.

Someone’s getting it.
It’s about crush height and interference holding the bearing. Looks to me like the one pictured, the tolerances were off at assembly and went south. Even if you put a retainer in that particular case with new bearing. It’s still not going to work and get spun .

The holding power is in crush height and interference with set bearing to the alloy. When this is proper as most are, that bearing ain’t going nowhere and no need for retainer.
 
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