This is an absolute bummer, I was hoping this engine would set the bar! Then Cat would come out with a 850+ engine and re-establish it! The 74 MM stroke looked like the right way to go and just increase bore to go larger! Too bad there are a few overlooked items, but I am sure it will be corrected due to posts! Just think if you make it thru to the spring, just hammer it home and maybe you will have a new engine for next yr! Oh a question for Dan, what is the cylinder plating thickness that is applied before hone? I do recall you remove about another .0003 -.0004 to achieve final finish? Just wondering what is left of plating thickness? And is it .0003 -.0004 of surface or total dia. removal? Have a happy holiday! Mike
850 gone down already??
- Thread starter ANTHONY11
- Start date
Mods - Is there any way to start a thread with a "poll" that could track engine failures based on failure, delivery date, and delivery location? I would be very interested to see, based on the fact that Poo has had issues getting sleds to people.
I'm betting you're pretty close to what actually happens in terms of the R&D of a new motor. I'd speculate that the "step 2" motors are the ones that have been running for years that Polaris bragged on so much at the introduction, and are a better built motor than at least some of the production 850s. They're the ones that are going to be hand-checked, honed, finished, and all, with a lot of attention to detail. It's quite possible Polaris did a very good job designing the engine, and the "we've had hundreds of prototypes running for thousands of miles a piece" claims are pretty accurate. But it's quite possible that the production engines are actually worse. It could be teething issues involving cylinder finishes, assembly procedures, and such concerns that'll be quickly worked out. It could be that the 850 has some design weaknesses that make assembly errors more likely and/or fatal. Or maybe a handful of failures are being blown out of proportion; without tearing down at least a dozen motors off the line or waiting a few months, I don't think anyone can be certain yet. I definitely agree that it's unfair to say the engineers screwed the pooch until we have more hard numbers on the failure rate.
As far as Dan's "fixes," they may be overkill for an OEM, but they're the sort of thing I would definitely spend money on. I might be an outlier in that I like wrenching on my own stuff, but imagine the following: I buy a blown Pro for $2K. I send the motor to Dan to be built into a bulletproof long rod motor – another $3.5K. I spend another $2k going through all the consumables (motor mounts, bearings, bushings, etc.) and any essential upgrades. I've spent half the price of a new 850; I have a sled that's not quite as good to ride, but significantly less likely to go down on me (wait, that's what she said), and I have more money in my pocket for other things.
Maybe it's just me, but I don't mind spending more on something significantly less likely to fail. It takes up most of the weekend for me to get in a good day of riding, and I don't go every weekend even though I'm closer than many. My current sled has been pretty "pull and go" (knock on wood), and that means a lot to me. The kind of refinement Dan's talking about would add maybe $500 to the price of a new 850; you might not get to the same level in mass production, but I'm sure we'd agree Polaris has room for improvement. Let's bump that number up to $1000, call it markup. Now, show of hands, who'd pay $1000 more for an "850 bulletproof" that was brought up to Dan's standards? If I'm paying $15k for a new sled already, that's not a hard choice for me...
To all you guys with new 850s that have blown up I feel for you. That’s really got to be a gut punch, especially if you are a 1 sled guy, only buy new once in several years or really had to budget or work OT or extra jobs if you are self employed to swing a brand new sled. In the world of problems this is definitely a first world problem but I know it has to feel sheety to have it happen.
Hope the repair, replacement, recall or whatever Poo does to make it right is as painless and trouble free as is humanly possible.
Hope the repair, replacement, recall or whatever Poo does to make it right is as painless and trouble free as is humanly possible.
That is probably one of the most constructive posts on this thread.
It sucks, but Polaris guys (that I know) love the things so much that they will not jump ship. They just know, and admit, that they need backup sleds. Both the guys I am talking about have their 850 sleds, as well as their old 800 sleds, and their wives' 800 sleds just in case.
As a Doo guy, I will always have a backup also. At least one. I remember in 2015 I had three new sleds in the shop and nothing to ride, they were all waiting on shocks or something.
I hope Poo and Doo get their sheet together, Cat is coming back, the Alpha is legit from my short ride on one.
I have one friend that locked his up in 50 miles. I thought he had it bad until I stopped at a buddies doo dealership and he is short 30 sleds. A bunch are snow check sleds. At least Coulter got to put 50 miles on his. Hopefully they remedy it quickly.
In our group we all ride Polaris, since the triples and before, new sleds every few years,we all work/have worked in the race engine world, we all can work on them ourselves and we all can pull the engines apart and rebuild them. If there is one thing we have learned dealing with Polaris is never to buy a first year motor from them, period zero exceptions.( probably other manufactures as well) I really feel horrible for guys who have issues with their new sled, hopefully they get it resolved quickly and replace the motors asap.
Nice post.
We're at nearly 500 posts, and nobody has come on here making fun at other's expense.
That's amazing.
Our shop Christmas party, we had a guest with inside info
More really interesting info to come on the 850 bottom end.
I can't get into it until after our Christmas company is gone.
Dan
More really interesting info to come on the 850 bottom end.
I can't get into it until after our Christmas company is gone.
Dan
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Great question
The answer is yes.
And this has been the buzz at our shop when we took the first one apart.
2 months ago.......( We said the floating PTO bearing was a death sentence during the assembly process. )
And I could not understand how this type set up was possible with no PTO bearing positioning implemented into that bearing.
Chances are the bearing can move under heavy loads even if positioned correctly in assembly......
No locker is REALY risky.
I knew our shop sleds would have to be torn down and the PTO bearing had to be locked...... Or it would forever haunt me in the back of my head.
To date .....I have never seen a floating PTO bearing on a crankshaft that didn't either have a lock ring or a locating pin.
I could not mentally be able to take the sled on a long trip and believe in it until it had locating element put in place.
Dan
The answer is yes.
And this has been the buzz at our shop when we took the first one apart.
2 months ago.......( We said the floating PTO bearing was a death sentence during the assembly process. )
And I could not understand how this type set up was possible with no PTO bearing positioning implemented into that bearing.
Chances are the bearing can move under heavy loads even if positioned correctly in assembly......
No locker is REALY risky.
I knew our shop sleds would have to be torn down and the PTO bearing had to be locked...... Or it would forever haunt me in the back of my head.
To date .....I have never seen a floating PTO bearing on a crankshaft that didn't either have a lock ring or a locating pin.
I could not mentally be able to take the sled on a long trip and believe in it until it had locating element put in place.
Dan
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S
snowmobiler
Well-known member
crankcase compression might be blowing oil lines off.
Only one has from what I have read. Just spewing his usual cat piss.
Please stay on topic Kelsey !!
If this floating crank bearing was this bad. Why didn't it show up in the preproduction motors that were running around last year. Some guys ran the 850 for a full season last year under cover?
And why has the floating bearing not been detramental on the previous polaris engines. I have a hard time believing if the cases are machined with the correct amount of crush that the bearing will move. I believe it would be easy to install wrong without having some sort of locating pin or retaining ring. This has been one of the most informative threads to date but trying to use the information to form my own theory and like stated above I don't believe the bearing could move if all the machining is correct.
Originally Posted by ADDIE View Post
Didn't the 2001-2005 Cat 800 and 900 Twins utilize a floating bearing? But I recall they has a locating pin as well?
KTR, How is this not EXACTLY on topic????? Just because Addie said it??
Didn't the 2001-2005 Cat 800 and 900 Twins utilize a floating bearing? But I recall they has a locating pin as well?
KTR, How is this not EXACTLY on topic????? Just because Addie said it??
for this to happen, would it be due to excessive blow by? Or is that what you think is causing it?
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