Gulp...
850 gone down already??
- Thread starter ANTHONY11
- Start date
Here's a good article on cylinder bore surface finishing ... Pretty well backs up everything Dan just said 
https://www.enginebuildermag.com/2000/09/cylinder-bore-surface-finishes/
That's geared more towards 4-stroke automotive engines, but I think the theory still applies
https://www.enginebuildermag.com/2000/09/cylinder-bore-surface-finishes/
That's geared more towards 4-stroke automotive engines, but I think the theory still applies
S
skippy
Well-known member
Well since I am still awake.......why wait ?
Not adhesive....... Well most likely not..... Read on
I beleive within 99.9% that what I am about to say will make things pretty clear why some sleds fail almost instantly and some are still running.
When you assemble an 850 bottom-end ...... It's much different then any other Polaris bottom-end.
When you set the crankshaft in the case..... Almost all people set it in the bottom half first because of the rods.
Install the MAG & PTO seal and set it in..... Correct?
Well.... Not so fast, remember this crankshaft has a floating PTO bearing.
If the bearing happens to be all the way ( in ) up against the crank wheel the motor will not make thru the first day, the stationary outer race will drag on the wheel and friction lock it.
If the bearing is dead center between the wheel and the crank seal you can ride a long long time.
If the bearing is all the way out as far as it will go it covers up 80% of the hole from the brass oiler....
( On the cases I have here )......... Now if by chance if an assembly line worker puts fair amount or sealer around the PTO seal its possible the remaining 20% of the hole is closed off. ( I believe this is very unlikely )
Or if by chance..... multiple shops were contracted to final machines the crankcase castings and there oil hole location was .100 to .150 thou inward from the cases I have here...... then the oil line will pop off because the bearing closed the hole. ( this is very possible )
I will post pics tomorrow of what it all looks like on one that's here.
In order to assemble These motors with the bearing in the exact same place
( the center between the wheel and the seal ) you would need to use a portable spacer between the crank cheek and the bearing until you have it seated.
Then pull the assembly spacer before installing the case top.
As I mentioned earlier..... A floating PTO bearing is a death sentence.
And besides all this....... Even if assemble dead center the chances of it staying there with the slide hammer effects of the drive clutch is almost zero.
The bearing would have to be Loctited in the case..... And Loctite expands and uses up space and can over crush bearings.
Very risky move.
Bed time.
Dan
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Here's a good article on cylinder bore surface finishing ... Pretty well backs up everything Dan just said
https://www.enginebuildermag.com/2000/09/cylinder-bore-surface-finishes/
That's geared more towards 4-stroke automotive engines, but I think the theory still applies
Nice article. Also backs up everything that I have been saying, go figure.
I will re-iterate. The OEM honing finish is a plateau honed finish.
A Plateau finish is needed and is provided with the OEM finish.
Dan's finish is a finer finish than the OEM finish. Again, both are a plateau finish.
The OEM hone finish will not wear pistons because the piston never touches the cylinder wall (also pointed out in the referenced article). The rings also never touch the cylinder wall directly (also pointed out).
So, while Dan's finish is finer, does it offer an advantage? Good question. It might and it might not.
It does not matter. WHY? Because the OEM hone finish does not cause piston failure as stated by Dan.
You guys can believe whatever you wish, but try and investigate the subject before believing everything that is written. Get some education on it (like the referenced article) that details the process and how the piston never touches the cylinder wall.
Keep in mind, that article seems to be directed to a cast iron surface. but, no matter what the surface most of the same principles apply.
Did I mention that the OEM hone finish will not cause piston wear or failure? Just checking.
Gotta say, I completely understand this customer. No matter how quickly and effectively the dealer fixes a blown-up sled, it's a big hassle for the owner (unless it blows a split second before you shut it down after loading up at the end of the day). If money was no object, I'd probably do what he's doing. I hate the thought that any machine I own could be a ticking time bomb. The fact that somebody would go through that kind of trouble and expense over Polaris's manufacturing and service says something about how much we trust Polaris to build motors.
Obviously a hand-built engine from a reputable builder still trumps a mass-produced engine, and I know a mountain two-stroke has a difficult life, but it's a little disappointing that Polaris seems content with the fact that they can't/won't/don't build an engine that can survive a user like TRS. I fly airplanes, and they do just fine at 100% power for hours on end. Of course, the dirty not-so-secret is that Polaris could do nearly that well, but maximum profit comes from building to a price and paying out to the 5% who run them hard enough to expose their weaknesses.
That said, I don't think we'll be able to reach any definitive conclusions until at least the end of the season. It could just be Polaris has rushed to meet demand and a handful have been shoved through with manufacturing defects. Also, the number of changes we see in the 2020 850s will be quite telling (although we may not know what those are until this time next year). I did have high hopes that the 850 would be a double-whammy of more power and durability/reliability (not expecting turbine-like lifespan there, just better than the 800), and I think that's still possible.
Still, all this does make my old 600VES shine a little brighter. After reading what Dan said about carbureted vs. injected, I wonder if that might outlast a new sled (heck, I just checked the runout, and at 4500 miles it barely moves the needle). I do find him a bit opinionated, but when he says something works I gotta believe him, plus my clutch came back after their service looking better than new. Actually for my next sled, even if the 850 pans out and I have the money, I might buy a blown Pro and send the motor to Dan. I'm a sucker for the "built not bought" approach!
Patriot Video
Funny you should post that skippy....... I was just watching that video a few days ago.
That video is part of the reason we are all here at this place on Snowest.
I was so disgusted by those two paid Actors mouthing off how great the ( PTO ) bearing is....( JESUS ) ��
Neither one of them are qualified to speak accurately in the video.
To sit there and pound spirited crap they both rehearsed over and over up the publics butt to suck them in... ( to which none of it was proven on the PTO bearing )
I wasn't going to say a word I was just going to watch it all unfold.
But after seeking that video and knowing what I know I went bat$hit crazy and stated my plan to unhinge Polaris never ending ploy to market untested products.
And that bearing wasn't hardly tested at all in the field......
95% .....So many great ideas.
But 5% guess work and GEE it looks great on the CAD model.
10,000 hours on a Dyno will never show the slide hammer effects of a CVT drive clutch on the PTO bearing ( it can slide the PTO-end off the rod pin ) if the fit isn't good enough.
Floating PTO bearing..... You have got to be $hitting me....... ( without a position lock )
WATCH THE VIDEO AND REALLY THINK ABOUT THIS PTO BEARING.
I THINK WE SHOULD START A CLASS ACTION LAWSUIT AND THAT VIDEO WILL BE WHAT WINS THE CASE & DRIVES POLARIS STOCK VALUE DOWN.
I guess if every thing they do is about the stock price, I could be the same kind of prick think only about Polaris stock
From the other angle.
Dan
And damn-it I still think it's a GREAT motor.
Funny you should post that skippy....... I was just watching that video a few days ago.
That video is part of the reason we are all here at this place on Snowest.
I was so disgusted by those two paid Actors mouthing off how great the ( PTO ) bearing is....( JESUS ) ��
Neither one of them are qualified to speak accurately in the video.
To sit there and pound spirited crap they both rehearsed over and over up the publics butt to suck them in... ( to which none of it was proven on the PTO bearing )
I wasn't going to say a word I was just going to watch it all unfold.
But after seeking that video and knowing what I know I went bat$hit crazy and stated my plan to unhinge Polaris never ending ploy to market untested products.
And that bearing wasn't hardly tested at all in the field......
95% .....So many great ideas.
But 5% guess work and GEE it looks great on the CAD model.
10,000 hours on a Dyno will never show the slide hammer effects of a CVT drive clutch on the PTO bearing ( it can slide the PTO-end off the rod pin ) if the fit isn't good enough.
Floating PTO bearing..... You have got to be $hitting me....... ( without a position lock )
WATCH THE VIDEO AND REALLY THINK ABOUT THIS PTO BEARING.
I THINK WE SHOULD START A CLASS ACTION LAWSUIT AND THAT VIDEO WILL BE WHAT WINS THE CASE & DRIVES POLARIS STOCK VALUE DOWN.
I guess if every thing they do is about the stock price, I could be the same kind of prick think only about Polaris stock
From the other angle.
Dan
And damn-it I still think it's a GREAT motor.
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Still waiting to hear what Addie’s qualifications and field of expertise are.
S
skippy
Well-known member
My guess is that "Addie" is probably one of the guys in the Polaris video I posted above...lol
Polaris CAN afford the worst case scenario. Money will NOT run out.
Of course nobody answering to stockholders wants to have to give that report at the board meeting.
In the real world, I would guess half of these were bought by flatlanders and won't see500 miles this season or1,500 miles in the warranty period.
It'll be interesting to see how they react regarding non-failure sleds.
But I will repeat, they are not a cash poor company.
Of course nobody answering to stockholders wants to have to give that report at the board meeting.
In the real world, I would guess half of these were bought by flatlanders and won't see500 miles this season or1,500 miles in the warranty period.
It'll be interesting to see how they react regarding non-failure sleds.
But I will repeat, they are not a cash poor company.
Yet we have a picture of a coated piston with the finish rubbed off. It had less than 10 minutes of run time. If the piston is not riding on the cylinder and in fact never touches it, what rubbed the coating off, the oil barrier?
It definitely will not sink them, they have been through it before a couple of times on the 900 and the dragon. It may give people a little more pause before purchasing though and will very likely cause some sales to shift to other brands. I bought three new Poo's in a row 13,14,16 before I had enough of the poor quality and reliability and switched brands. Best sled decision I ever made was not checking an 850.
It could definitely cause them to lose that top sales spot and consequently their bottom line.
I have refrained from posting this because it’s not actually my sled that it happened to but my brother in laws. I know on snowest even if it’s your wife’s sled and you don’t have pictures to prove it many will say you are a liar but here goes anyway.
4 weeks ago my brother in law lost the crank in his 850 after 3.2 miles. His dealer told him that Polaris is sending a new motor immediately because they had recently found out an assembly line worker had not been using a spacer when assembling the cranks and the effected motors would loose the cranks fairly quickly. They claimed it was an isolated incident and there were approximately 50 problematic motors. Sounds like there could be more to it though. No I don’t have pictures, no I wasn’t there when it happened but it happened none the less whether anyone chooses to believe it. Its sad we live in a Snowest world now where many people won’t post things they know to be true because they don’t have pictures and don’t want to deal with people accusing them of making the story up.
When this discussion turned to PTO bearings and then IndyDan starts talking about a spacer that would need to be used assembling these it all made sense. Now I am not an expert by any stretch of the imagination. I don’t even ride a Polaris but I do enjoy learning from people who are infinitely smarter than I am and I have appreciated all the information from everyone on both “sides” of this debate. Threads like this are what made Snowest great years and years ago and it’s nice to see something like this again so we can all hopefully become a little bit more informed on the inner workings of a motor. Who else is just happy to not be reading another which oil is the best thread?
4 weeks ago my brother in law lost the crank in his 850 after 3.2 miles. His dealer told him that Polaris is sending a new motor immediately because they had recently found out an assembly line worker had not been using a spacer when assembling the cranks and the effected motors would loose the cranks fairly quickly. They claimed it was an isolated incident and there were approximately 50 problematic motors. Sounds like there could be more to it though. No I don’t have pictures, no I wasn’t there when it happened but it happened none the less whether anyone chooses to believe it. Its sad we live in a Snowest world now where many people won’t post things they know to be true because they don’t have pictures and don’t want to deal with people accusing them of making the story up.
When this discussion turned to PTO bearings and then IndyDan starts talking about a spacer that would need to be used assembling these it all made sense. Now I am not an expert by any stretch of the imagination. I don’t even ride a Polaris but I do enjoy learning from people who are infinitely smarter than I am and I have appreciated all the information from everyone on both “sides” of this debate. Threads like this are what made Snowest great years and years ago and it’s nice to see something like this again so we can all hopefully become a little bit more informed on the inner workings of a motor. Who else is just happy to not be reading another which oil is the best thread?
I want to start off by saying what my experience is and what I do. I have been in the mechanical industry 30 years and my job is Field Technical support to engineering and design teams for one of the largest manufactures in the world. We work as a team but there are some days when I have to tell members of my team that their "Baby is ugly". Now no one likes to hear that no matter what you do but some days its the truth.
With the latest find on the PTO bearing not having a locating device Polaris is asking for a black eye. It's not going to be IF its going to have an issue its WHEN. Thank God I didn't purchase the first year 850...……….
So for you handful of Polaris engineers that are on here lurking and posting I am going to use a phrase a peer of mine uses.
"Not only is your Baby Ugly...YOUR MOMMA IS UGLY on this one"
With the latest find on the PTO bearing not having a locating device Polaris is asking for a black eye. It's not going to be IF its going to have an issue its WHEN. Thank God I didn't purchase the first year 850...……….
So for you handful of Polaris engineers that are on here lurking and posting I am going to use a phrase a peer of mine uses.
"Not only is your Baby Ugly...YOUR MOMMA IS UGLY on this one"
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Probably not me. I would be more apt to go with the Alpha cat. I just don't like that Doo chassis. I also have to many friends that ride them and keep patting themselves on the back because the ride the greatest brand ever. Its pitaful how biased they are. LOL.
4 weeks ago my brother in law lost the crank in his 850 after 3.2 miles. His dealer told him that Polaris is sending a new motor immediately
So have you talked to your brother in law and did he get it running again? I would think Polaris has 50 spare motors, but as winter comes on, will they run out? Sounds like the whole motor is a mess when you lose a crank bearing.
thanks
So have you talked to your brother in law and did he get it running again? I would think Polaris has 50 spare motors, but as winter comes on, will they run out? Sounds like the whole motor is a mess when you lose a crank bearing.
thanks
Following this thread just out of curiosity but thought I would chime in with a remotely connected thought.
I for one doesn't doubt Dan when he says he knows more than the engine engineers at Polaris regarding for example surface texture in coated cylinders, this since he has probably been doing this for more than twice as long as the engineers at Polaris, (or any other OEM for that matter).
The reason for this is that in these big companies the personell move around a lot, an engineer needs to be really special, (perhaps in more ways than one), to be kept, or left, at one place for more than a few years. I'm in engineering and I work for a small company that has a lot of really big companies as customers, and we see this a lot. A customer develops a new product, uses our component, has some initial adjustment problems but eventually sorts everything out. A few years later the same customer develops the new generation of product, all of the previous lot of engineers has moved along to new positions, and the new lot almost with 100% certainty repeats the mistakes that were made before, because to them they are new mistakes.
I for one doesn't doubt Dan when he says he knows more than the engine engineers at Polaris regarding for example surface texture in coated cylinders, this since he has probably been doing this for more than twice as long as the engineers at Polaris, (or any other OEM for that matter).
The reason for this is that in these big companies the personell move around a lot, an engineer needs to be really special, (perhaps in more ways than one), to be kept, or left, at one place for more than a few years. I'm in engineering and I work for a small company that has a lot of really big companies as customers, and we see this a lot. A customer develops a new product, uses our component, has some initial adjustment problems but eventually sorts everything out. A few years later the same customer develops the new generation of product, all of the previous lot of engineers has moved along to new positions, and the new lot almost with 100% certainty repeats the mistakes that were made before, because to them they are new mistakes.
Great post..... And yes sometimes the truth is hard to except.
You know there has been ( a lot of people at Polaris ) up until the day before yesterday that had their chests pushed out and walking tall about the 850
And now they sit quietly at their desk hitting the fresh button on Snowest.
This is the part about Polaris that has always been hard to swallow.
Their never ending arrogance about a new product before the public has even had a real chance at it on production units.
LETS MAKE SURE WE ALL KNOW ONE KEY THING HERE.....
This is NOT an assembly line error........ NO WAY NO HOW ! Not a chance this is a engineering flaw.
And who ever he is..... She..... Them..... All involved in that PTO bearing should have their pay cut down to minimun wage and moved to sweeping floors and cleaning toilets for at least 2 years for all to see ( not moved to a different engineering job )
The two guys in the video should be sent up to the county jail for a few weeks for racketeering.
Dan
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