Install the app
How to install the app on iOS

Follow along with the video below to see how to install our site as a web app on your home screen.

Note: This feature may not be available in some browsers.

  • Don't miss out on all the fun! Register on our forums to post and have added features! Membership levels include a FREE membership tier.

850 gone down already??

We unloaded our our new 174" - 850 and pulled the head to check the bench volume..... Found the cylinder finish to be as bad as the 2008 Dragon motor.

It's seems so strange that this would happen..... Polairs was really starting to show progress on the 800 cylinder finish....

Not all of them.... but a really good percentage were pretty good.


Ok, here is a picture of a new 850 we just drove in the shop ZERO miles

And 4 pictures of 800 small block cylinder cylinder we just honed for comparison.

They both looked about exactly the same before honing....

Can you please clarify?
 
How can Polaris state that they had so many miles and so many hours on these NEW engines and we are seeing, maybe, some bad gu gu coming. There has to something different from the R & D engines to the production engines for the new 850’s.

It doesn’t matter what manufacture it is, customer confidence will suffer! Sales will drop/suffer. Even with full warranty the dealers will end up taking the wrap for these issues that are coming up. It doesn’t matter what brand of snowmobile you ride, what brand of truck you drive or what brand of suv your wife drives someone has issues. For all the years that these manufacturers have been building engines, one would think they could get it right.

Indy Dan might be onto something. He is as good as they come when it comes to Polaris. As Dan stated, low snow conditions, will not show the all the issues that might arrive.

It is almost the first of January and we have 55* here in Casper, Wyoming. No snow in the forecast for at least a week. The snow that there is around is used up for sure. Should make a good base if it ever snows again.

I hope for ALL 850 riders this year that the issues are small.
 
Here is what the graffle coating looks like from the trailer to the shop on our new 174 850

under 100 feet.

The missing coating is what you see on the cylinder push up towards the top
by the ring.

Dan

looks like rubbing marks going horizantally on that piston?
that's too bad if its every 850. maybe they'll get recalled for new top ends, that wouldn't hurt them too bad in the end.
 
The Polaris cylinder and s Ski Doo cylinders are both plated and manufactured at the same plating house.

While a smoother finish might help things, it is not required. The Ski Doo pistons (also single ring) do not suffer from skirt rubbing due to a poor plating finish. Why should the Polaris?

All piston ring must smooth out the highspots in any plating. This happens mainly during the 1st 300 miles. For the these early miles the rings and plating will take some abuse because they are being fitted to each other.
This is not of big concern.

The piston and ring always ride on an oil barrier, otherwise they will fail in short order.

The coating on the piston is a break in coatin that is present just for this reason. It is designed to wear off during break in. Again, it is its purpose.

The single ring Polaris piston is not as good as the Ski Doo Single ring piston and the Ski Doo piston is not very good. This Polaris piston will suffer some ring failure and blow by for sure. The piston is also extremely heavy and will retain heat and this can lead to skirt collapse.

None of this is cured by a better hone finish.

This scare tactic is just that.

The 850 engine, IMO, will have some issues but they are not related to the cylinder honing process.
 
Would like to have a microphone in the room as the poo engineers share this thread - you know they follow this board. AC and Doo are peeking, too.

Rest assured, the pre-production motors last spring were hand built. Line production is a whole 'nuther animal. If widespread, Poo will work their way out of this - while they deny the issue, unless they have a mass update. Wouldn't be the first time an OEM had a major mass update (e.g., first year S3 Rotax 800 twin), but this would be pretty messy. Helps that this was a limited build spring-only motor, by design.

Thanks for taking the time to share and post the pics, Dan. It's not like you have to - but more pics will certainly be surfacing around here now. Gentlemen, start your cameras.
 
The Polaris cylinder and s Ski Doo cylinders are both plated and manufactured at the same plating house.

While a smoother finish might help things, it is not required. The Ski Doo pistons (also single ring) do not suffer from skirt rubbing due to a poor plating finish. Why should the Polaris?

All piston ring must smooth out the highspots in any plating. This happens mainly during the 1st 300 miles. For the these early miles the rings and plating will take some abuse because they are being fitted to each other.
This is not of big concern.

The piston and ring always ride on an oil barrier, otherwise they will fail in short order.

The coating on the piston is a break in coatin that is present just for this reason. It is designed to wear off during break in. Again, it is its purpose.

The single ring Polaris piston is not as good as the Ski Doo Single ring piston and the Ski Doo piston is not very good. This Polaris piston will suffer some ring failure and blow by for sure. The piston is also extremely heavy and will retain heat and this can lead to skirt collapse.

None of this is cured by a better hone finish.

This scare tactic is just that.

The 850 engine, IMO, will have some issues but they are not related to the cylinder honing process.

I am willing to make a bet with you......to see who is right.

I have zero to gain by scaring anyone.

I have more work then we can handle for the next 3 months.

7 guys and the shops to small........are you deaf ? i said we can't hardly keep are heads above water now.

Trying to stay out of trouble on social media what we are trying is Warp speed processing of orders people still get pissed from time to time ( when someone slips thru the cracks. )

I'll make a forum statement and a dare....

Find 2 guys that have 850 sleds ( That ride 3000 plus miles per season )

Leave one completely stock, and i'll hone the other one and we will soon see who is correct.

You see you think you're right..... I know i am right. I have seen this same program and its still fresh in my mind from the few hundred grand i lost.

It really doesn't matter if God himself plated all the 850 cylinders... its who honed them and what state ( condition ) the super abrasives are in.

New stones.....? broke in stones to full contact radius.....? Honing oil ? grit ? finishers ? how many finishers ?

From what i have seen....This is a full blow honing emergency.

Pick 2 guys and we will have a little gentalmens bet.....

My guess is this...........the OEM cylinder won't make 1/2 season and the one i hone will just make it at least 3 seasons.

My vote for one tester is TRS Tony ( 4000 plus miles per season in the mountains )

He makes a career out of ruining Polaris OEM motors... namely pistons.

Tell me what i gain by fear mongering ?

The motors are under warranty for 4 years.... that means NO ONE should be touching then until 2023

The guys that have seen this problem are already sending them here for honing.

Its not exciting its ****ty work and very time consuming to process.

When OEM's start talking ( special break-in proceedure ) you better grab your ass because the trouble is coming.

And whoever wrote the new Polaris break-in update proceedure is nuts !!

Ok.... lets NOT put oil in the fuel.... then lets make its as rich as possible by putting it in ethanal mode.... ( and wash the oil off the cylinders excess fuel )

That's Brilliant..... What should be done is this.

Correct plateau finished cylinder ( just slightly rich fuel delivery for one tank of pre-mix only ) just to insure oil pump is all primed.

Then the sled should go to stock fuel delivery with no oil in fuel, oil pump 5% above normal for 150 miles then away you go.

Cast iron rings do NOT break in silicon carbide cylinders...... silicon carbide cylinder destroy everything except diamond.

They do however wear out diamond over time..... ( the Nicasil cylinders actually wear the diamond shoes )

So your post is heart warming to call off the pressure on what polaris will soon feel. ( if the cylinders are all this rough )

We will all soon see who is right or wrong.......I am praying for a HUGE snow fall winter.

If it snows there better be a huge stock of 850 pistons.

I own a new 850 i was hpoing to NOT touch the first year, this shop has 2 of them.

Dan
 
Last edited:
th
 
ADDIE: I don’t want to start a pissing match but I do have a guestion for you: where do you get your knowledge from? Are you an engineer or a qualified machinist with 1000’s of hours on working on snowmobiles atv’s?

Thank you for your time and reply.
 
This bothered me enough I had to put the scope in mine tonight.... fyi, it's a poor quality scope. The piston coating was coming off but I think the pistons looked fine. Lots of oil on everything. I had a video of them with me turning the clutch by hand but can't seem to get it to load. 2.4 hours, low miles, warmed up well before riding. Dont know what to think right now. I'm going to call my dealer tomorrow and see what the service guys will tell me, but as of right now, I'm just gonna run it like I stole it and have fun trying to beat up on my buddies doo's and cats while I can.

20181217_182323.jpg 20181217_182311.jpg 20181217_182137.jpg 20181217_182051.jpg
 
Last edited:
That's kinda scary .. makes one feel good with Four Year Warranty and 2020 on it's way !!

Factory Turbo Sub 400# . First to let FlaggerBook know :eyebrows:
 
This bothered me enough I had to put the scope in mine tonight.... fyi, it's a poor quality scope. The piston coating was coming off but I think the pistons looked fine. Lots of oil on everything. I had a video of them with me turning the clutch by hand but can't seem to get it to load. 2.4 hours, low miles, warmed up well before riding. Dont know what to think right now. I'm going to call my dealer tomorrow and see what the service guys will tell me, but as of right now, I'm just gonna run it like I stole it and have fun trying to beat up on my buddies doo's and cats while I can.

All the load is on the intake skirt..... that is where all the pressure is applied from combustion.

Much harder to check.......you have to pull the air box, throttle bodies, and red boots & reeds.

I can safely say..... if you have several good rides on it and the intake looks the same as the exhaust side you should be good to go.

If the power is falling off & you need less clutch weight the writing is on the wall.

It needs pistons........that how the small block 800 acts.

The 850 will tell the same story.

Dan
 
This bothered me enough I had to put the scope in mine tonight.... fyi, it's a poor quality scope. The piston coating was coming off but I think the pistons looked fine. Lots of oil on everything. I had a video of them with me turning the clutch by hand but can't seem to get it to load. 2.4 hours, low miles, warmed up well before riding. Dont know what to think right now. I'm going to call my dealer tomorrow and see what the service guys will tell me, but as of right now, I'm just gonna run it like I stole it and have fun trying to beat up on my buddies doo's and cats while I can.

Don’t worry about the coating on the pistons. It never lasts on any engine.

Let me just submit this. I have seen big temperature variations on my sled. They moved the thermostat to the coolant bottle instead of the head. Can this bring temp inconsistencies large enough to have sleds seizing in certain conditions?
 
Kinda doubt it....I can’t even imagine how many people ran severely overheated Pro chassis sleds and never heard of any seizing on those.
 
Premium Features



Back
Top