• 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??

diamonddave

Chilly’s Mentor
Lifetime Membership
Apr 5, 2006
5,569
3,866
113
Wokeville, WA.
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.



While I hear what you are saying, it's apples and oranges. Those motors had pistons that quickly developed tons of piston to cylinder clearance. PI was still nervous from 08-09 Dragon's.
 

diamonddave

Chilly’s Mentor
Lifetime Membership
Apr 5, 2006
5,569
3,866
113
Wokeville, WA.
Wonder what kind of fix kit “Mr I Climb Hills Squating” will come up for this. Guess I will never know since I got kicked off his FB club.



Hahahaha....this is awesome. Except he doesn't call his no name pistons a Fix Kit. MTNTK did that and brought great tech with theirs.
 

sledhead_24_7

Well-known member
Lifetime Membership
Premium Member
Jul 30, 2008
2,480
996
113
Jackson Wy
The Polaris cylinder and s Ski Doo cylinders are both plated and manufactured at the same plating house.


Not true, at least any more. Skidoo switched over the Plasma Arc cylinder coating on their 850 as well as their new 600.

Here is a link to a video showing the process, around 2:00 min.

https://youtu.be/wy-4xsBNe9w

Another from Ford using the same process.

https://youtu.be/yBl5mYMsBSI

It is a bit discouraging to here the possible bad news. I was hoping Polaris was going to get things figured out this go around. Since I was thinking of trying one next year if things worked out. No way I was going to be a first year test dummy, Polaris got me too many times on that front, to do that again.
 

indydan

Well-known member
Lifetime Membership
Nov 27, 2007
1,245
3,301
113
Custer, South Dakota
www.indyspecialty.com
Pull the head

IndyDan - What can we do to improve the reliability of our 850's? Is there an easy check (such as pulling head, etc) that us half mechanics can do to monitor this moving forward?

The sled is really easy to work on, removing the head and cylinder super easy takes only a few minutes.

I would pull the head and take a peak..... Take a few pictures from different angles..


Put the pics on Snowest..... I'll tell you what I would do if it was mine.

Dan
 

RMK-King

Super-Moderator
Dec 25, 2007
1,928
1,374
113
North Dakota
This seems like a fairly easy quality control fix for Polaris going forward if it does turn out to be a wide spread issue. Change the honing supplier back to who ever was doing it for the 800HO.


As a FYI a new 850 cylinder is $1056 and pistons are $250 EACH. Kinda makes a guy not want to void his warranty for awhile just in case.
 
Last edited:

94fordguy

Well-known member
Staff member
Lifetime Membership
Nov 26, 2007
14,576
5,244
113
38
Yakima, Wa.
I may be wrong as I don't recall where I read/heard it, but from what I recall, I thought there was some advertising that this engine has been in testing for 6 years and showed excellent results, the most heavily tested engine Polaris has ever introduced. Could something have changed such as a supplier or process from the experimental engines to the production engines that could explain the possible lack of quality/durability?


I'm a big Polaris fan, but even I'll admit to anyone who asks, Polaris has a pretty horrible reputation with new engine introductions. My next sled may not be a Polaris after all :eek:
 

kidwoo

Well-known member
Lifetime Membership
Dec 28, 2008
2,630
1,875
113
As mentioned, I'm sure the design is fine........and it's just cheaping out on production.
 

ADDIE

Well-known member
Premium Member
Nov 14, 2013
63
137
33
Dan, so you are stating that the piston skirt actually touches the cylinder wall and the aggressive hone finish will wear the piston due to this contact?

Is this what you are suggesting?

Are you also suggesting that the piston skirt coating should remain on the piston for its lifetime and that it is an indication of how the piston is fairing in the cylinder?

The bet you are suggesting is a losing bet for both ends. IMO, no matter what hone finish is applied, the piston will not survive 3,000 hard mountain miles. It will be far out of spec well before 3K in the mountains.
 

Big10inch

Well-known member
Lifetime Membership
Premium Member
Mar 11, 2018
926
888
93
Dan, so you are stating that the piston skirt actually touches the cylinder wall and the aggressive hone finish will wear the piston due to this contact?

Is this what you are suggesting?


Did you take a second to look at the picture of the sled that ran 100 feet into the shop? No "suggestion" necessary...



Are you also suggesting that the piston skirt coating should remain on the piston for its lifetime and that it is an indication of how the piston is fairing in the cylinder?

The bet you are suggesting is a losing bet for both ends. IMO, no matter what hone finish is applied, the piston will not survive 3,000 hard mountain miles. It will be far out of spec well before 3K in the mountains.

Pretty sure Dan offers a three year warranty on his motors with the HG7 finish and the claim is for 5000 mtn miles and 10,000 trail miles.


NONE of this is a mystery, Indy Dan has it all on his website for you to read. He also has the best rep of any engine builder for ANY brand that I am aware of.


Face it, you kind of stepped in it on this one.
 
C
Feb 8, 2008
241
60
28
How many 850 motors have been taken apart and inspected for the same issue?
Is it possible that the one that was taken apart has a manufacturing defect that does not exist in many of the other 850's?
 

indydan

Well-known member
Lifetime Membership
Nov 27, 2007
1,245
3,301
113
Custer, South Dakota
www.indyspecialty.com
Dan, so you are stating that the piston skirt actually touches the cylinder wall and the aggressive hone finish will wear the piston due to this contact?

Is this what you are suggesting?

Are you also suggesting that the piston skirt coating should remain on the piston for its lifetime and that it is an indication of how the piston is fairing in the cylinder?

The bet you are suggesting is a losing bet for both ends. IMO, no matter what hone finish is applied, the piston will not survive 3,000 hard mountain miles. It will be far out of spec well before 3K in the mountains.


ADDIE

To your first question - Yes actually I am - trust me we all wish that this was like the old days.....Where the piston actually rode on a cushion of oil. ( cast iron sleeve, induction of fuel thru the case mounted reed cage ) ..... * Oil injected into the throat of the carburetor *

Plenty of time for the spinning crankshaft to mix the oil and gas thoroughly

That being said, In vision in your head this for a moment.

In 2004 You shut off your Carburated 800 sled after a long day's ride and you hear it's going to be -30 below zero in Cooke City where you are riding. ( this sled is 130 Hp )

In 2011 you shut off your fuel injected sled after a long days ride and you hear it's going to be -30 below zero in Cooke city where you are riding. ( this sleds about 145 hp )

What's the big difference between the 2 sleds tomorrow morning after both sleds have sat all night and you go to start them ?

Let me paint a small picture for us all.

The 2004 has a wonder recipe of blended premixed laying in the bottom of the case that has drained down from shut off.... It's still thin and fluid @ -30 because of the fuel ( or Solvent which thins the oil ) it's actually just deep enough to where it most often touching the crank wheels and for sure the big rod end in the recess in the case....... You go to full choke and you start pulling and because it's so cold it takes a few more pulls then normal to start even though it fired once already from the past fuel & oil that pooled in the case.

The magic that happen while you were pulling ..... ( a thin recipe of fuel & oil was being splashed on the cylinder walls from the connection rod ) and the ice cold fuel following from the carb has oil in the throat from the little brass fitting in the carb. * this thin magic recipe is providing a instant layer of protection between the cylinder and the piston. *

The 2011 CFI 2 ( fuel injection sled ). Has straight injector oil in the crankcase with no fuel and it's thick * even VES gold was thick in 2011.....

Picture what's coming here...... The 2011 mid-cylinder mounted rear transfer fuel injector is just waiting for you ( the giant capacitor has stored a huge charge of electricity from the day before ) it's still there and it's ready.... You pull the rope once and it barely turned over the first pull.... WOW YOU SAY !! Well being that you are 30 years old and 6'-4" tall 275 pounds you anchor your foot in the stir-up and you are going to make sure that this thing spins fast this time & you just about ripe the recoil right off the motor....., IT STARTS ON THE SECOND PULL !

What just happened ? You start praising the EFI system to all your pals and you say good bye to the carburetor day..... ( what really happened ? )

The 2011 sled started on the second pull..... The rear mounted fuel injector on the first pull felt the energy from the capacitor and it opened the fuel pump spun from the stored energy in the capacitor and a fresh spray of ( dry ) fuel enter the
rear transfer port up high right by the rear transfer opening and what did it do ?

I'll tell you what the first thing is it did..... It washed any trace of oil left on the back of the piston off and blew it side ways around the piston where there is no load.... Oh wait NO PROBLEM ! The rod is coming around to throw a mix of oil and fuel on the cylinder walls ..... right ?

Wrong..... Remember there is no fuel in the case.... Only thick ICE cold injector oil ( and if by chance it's deep enough to touch the crank ) there is no way at recoil speed the ice cold injector oil can be thrown anywhere.

The oil is attached to a 29 pound ciclular chunk of steel that is -30 degrees below zero....... And it's going to be a while before it gets warm enough to throw oil.

So the 2004 800 ( exact same bore size )85mm that had a fuel blend in the case almost never needed Pistons ) because the piston was riding on a film of oil.

Verses a 2011 800 .... 85mm bore at start up the piston is ( if honed incorrectly ) non-plateau finish the piston is rubbing ( not riding ) on the razor sharp fracture peaks created by the ripping & tearing effects of diamond super abrasive honing shoes.

And even though the piston alloys are amazing and the piston surface is really really hard...... The silicon carbide can cut its way through after time.

And it takes many cold starts to cut through this...... That's why mountain sleds are so hard on Pistons ( many many starts for very few miles ) trial sleds very few starts for lots and lots of miles.

If you take a group of guys that trial ride together that are ( all on the wagon ) and REALLY ride and don't stop at ever 25 miles at a bar ) and roll on 350 miles per day these EFI motors will go easily past 12,000 I see it from time to time.

It's the cold starts that kill EFI sleds...... ( why do you the injector oil keeps getting thinner ? ) the thinner the cold start viscosity the better piston life you will see.

Ohhhhhh ! I gotta throw one little laugher in on the cold start 275 pound 6 foot 4" 30 year old that can start a -30 degree Polaris in 2 pulls.

Why don't we all buy electric start Polaris sleds ? OH THATS RIGHT I HAVE BOUGHT SEVERAL WITH E-START POLARIS SLEDS.....

Oh that's right..... The electric start doesn't work on a Polaris below zero !!

What was I thinking ??? :pizza::juggle:

ADDIE....... Do I really have to go into the piston coating thing ?

This will be another Novel ( let's just part with this for now ) it's break in coating .. Right ?

Don't get me started on coating...... Especially when we are dealing with a company that is on the NASDAG

Polaris - wrote the book on let's take the lowest bidder every time and then expect quality and dependability on the snow.

I will tell you this..... If I worked for Polaris heads would roll and there would be a house cleaning like you have never seen. Followed by a motor to the likes of nothing Polaris could possibly imagine.

And it really wouldn't be that hard..... 2 things would happen.

It would be done faster the they thought possible

And it would come in under budget ( a lots Art ) now days.
.
I gotta get to work.

( note ) I did not proof read this..... As you all know I am not a scholar.

And I never proof read until after I send it.... Then I re-read it later and say to myself ... OH MY GOD !!

Edit edit edit

Dan
 
Last edited:

TRS

Life Member
Lifetime Membership
Dec 1, 2007
4,098
6,229
113
67
Cody, WY
ADDIE

To your first question - Yes actually I am - trust me we all wish that this was like the old days.....Where the piston actually rode on a cushion of oil. ( cast iron sleeve, induction of fuel thru the case mounted reed cage ) ..... * Oil injected into the throat of the carburetor *

Plenty of time for the spinning crankshaft to mix the oil and gas thoroughly

That being said, In vision in your head this for a moment.

In 2004 You shut off your Carburated 800 sled after a long day's ride and you hear it's going to be -30 below zero in Cooke City where you are riding. ( this sled is 130 Hp )

In 2011 you shut off your fuel injected sled after a long days ride and you hear it's going to be -30 below zero in Cooke city where you are riding. ( this sleds about 145 hp )

What's the big difference between the 2 sleds tomorrow morning after both sleds have sat all night and you go to start them ?

Let me paint a small picture for us all.

The 2004 has a wonder recipe of blended premixed laying in the bottom of the case that has drained down from shut off.... It's still thin and fluid @ -30 because of the fuel ( or Solvent which thins the oil ) it's actually just deep enough to where it most often touching the crank wheels and for sure the big rod end in the recess in the case....... You go to full choke and you start pulling and because it's so cold it takes a few more pulls then normal to start even though it fired once already from the past fuel & oil that pooled in the case.

The magic that happen while you were pulling ..... ( a thin recipe of fuel & oil was being splashed on the cylinder walls from the connection rod ) and the ice cold fuel following from the carb has oil in the throat from the little brass fitting in the carb. * this thin magic recipe is providing a instant layer of protection between the cylinder and the piston. *

The 2011 CFI 2 ( fuel injection sled ). Has straight injector oil in the crankcase with no fuel and it's thick * even VES gold was thick in 2011.....

Picture what's coming here...... The 2011 mid-cylinder mounted rear transfer fuel injector is just waiting for you ( the giant capacitor has stored a huge charge of electricity from the day before ) it's still there and it's ready.... You pull the rope once and it barely turned over the first pull.... WOW YOU SAY !! Well being that you are 30 years old and 6'-4" tall 275 pounds you anchor your foot in the stir-up and you are going to make sure that this thing spins fast this time & you just about ripe the recoil right off the motor....., IT STARTS ON THE SECOND PULL !

What just happened ? You start praising the EFI system to all your pals and you say good bye to the carburetor day..... ( what really happened ? )

The 2011 sled started on the second pull..... The rear mounted fuel injector on the first pull felt the energy from the capacitor and it opened the fuel pump spun from the stored energy in the capacitor and a fresh spray of ( dry ) fuel enter the
rear transfer port up high right by the real transfer opening and what did it do ?

I'll tell you what the first thing is it did..... It washed any trace of oil left on the back of the piston off and blew it side ways around the piston where there is no load.... Oh wait NO PROBLEM ! The rod is coming around to throw a mix of oil and fuel on the cylinder walls ..... right ?

Wrong..... Remember there is no fuel in the case.... Only thick ICE cold injector oil ( and if by chance it's deep enough to touch the crank ) there is no way at recoil speed the ice cold injector oil can be thrown anywhere.

The oil is attached to a 29 pound ciclular chunk of steel that is -30 degrees below zero....... And it's going to be a while before it gets warm enough to throw oil.

So the 2004 800 ( exact same bore size )85mm that had a fuel blend in the case almost never needed Pistons ) because the piston was riding on a film of oil.

Verses a 2011 800 .... 85mm bore at start up the piston is ( if honed incorrectly ) non-plateau finish the piston is rubbing ( not riding ) on the razor sharp fracture peaks created by the ripping & tearing effects of diamond super abrasive honing shoes.

And even though the piston alloys are amazing and the piston surface is really really hard...... The silicon carbide can cut its way through after time.

And it takes many cold starts to cut through this...... That's why mountain sleds are so hrs on Pistons ( many many starts for very few miles ) trial sleds very few starts for lots and lots of miles.

If you take a group of guys that trial ride together that are ( all on the wagon ) and REALLY ride and don't stop at ever 25 miles at a bar ) and roll on 350 miles per day these EFI motors will go easily past 12,000 I see it from time to time.

It's the cold starts that kill EFI sleds...... ( why do you the injector oil keeps getting thinner ? ) the thinner the cold start viscosity the better piston life you will see.

Ohhhhhh ! I gotta throw one little laugher in on the cold start 275 pound 6 foot 4" 30 year old that can start a -30 degree Polaris in 2 pulls.

Why don't we all buy electric start Polaris sleds ? OH THATS RIGHT I HAVE BOUGHT SEVERAL WITH E-START POLARIS SLEDS.....

Oh that's right..... The electric start doesn't work on a Polaris below zero !!

What was I thinking ??? :pizza::juggle:

ADDIE....... Do I really have to go into the piston coating thing ?

This will be another Novel ( let's just part with this for now ) it's break in coating .. Right ?

Don't get me started on coating...... Especially when we are dealing with a company that is on the NASDAG

Polaris - wrote the book on let's take the lowest bidder every time and then expect quality and dependability on the snow.

I will tell you this..... If I worked for Polaris heads would roll and there would be a housing cleaning like you have never seen. Followed by a motor to the likes of nothing Polaris could possible imagine.

And it really wouldn't be that hard..... 2 things would happen.

It would be done faster the they thought possible

And it would come in under budget
.
I gotta get to work.

( note ) I did not proof read this..... As you all know I am not a scholar.

And I never proof read until after I send it.... Then I re-read it later and say to myself ... OH MY GOD !!

Edit edit edit

Dan

Spot on Dan.
 

tuneman

Well-known member
Lifetime Membership
Jan 16, 2013
1,167
1,205
113
Minnesota
www.everettsports.net
The sled is really easy to work on, removing the head and cylinder super easy takes only a few minutes.

I would pull the head and take a peak..... Take a few pictures from different angles..


Put the pics on Snowest..... I'll tell you what I would do if it was mine.

Dan
Spoken from the expert....geeeeez, Dan, I have major respect for your knowledge and talent, but taking cylinders off any engine is far from easy for the majority of garage mechanics. Please don't do this, unless you really know what you're doing or at least study up on it.

Polaris needs to hire Dan as a consultant. Seems like a no-brainer. Hello, Polaris, you listening?
 

indydan

Well-known member
Lifetime Membership
Nov 27, 2007
1,245
3,301
113
Custer, South Dakota
www.indyspecialty.com
Rod Ratios

Dan,
Is the rod angle worse in the 850 compared to the 800?

Tony, I will post the Rod ratios when I get a chance to look at my notes I have them all wrote down.

Since I am still sitting on the couch in my slob-wear typing to what mostly likely is a Polaris ( Engine-hear ) I am not where I belong standing next to my friend ( The Hurco VMX50 5 Axis milling machine. ?

The last time this happened was was on Snowest in the general section about the 900 crank and I schooled ( Larry H still an engine-hear at Polaris ) lead man on the twin firing ATV motor....Schooled him on th 900 crank and motor design.

Snowest pulled the thread ! This one has already gone to far to pull.

I had to wait long enough to get enough viewers vested to get to the fun stuff.

Ohhhh and the Rod ratio on the 850 motor is not good and I am building custom long rods for this motor as we speak...... And they will be ready this season and I will be putting a 3 year warranty on the complete motor including the Pistons.

Dan
.
 

indydan

Well-known member
Lifetime Membership
Nov 27, 2007
1,245
3,301
113
Custer, South Dakota
www.indyspecialty.com
Ohhhh I forgot to mention an important factor

Lastly on the 2004 800 big block verse the 2011 small block comparison


The 2004 85mm X 70mm stroke 800 bigs block carb motor

Verse the ......

The 2011 85mm X 70mm stroke 800 small block EFI motor

The rod ratio......

The big block rod had a 136mm center to center

The small block has a 132mm center to center

The 2004 800 carb 136mm rod almost never needed Pistons

The 2011 80@ EFI 132mm rod needed Pistons all the time in most production motors.

Indy Specialty's Torque Master 3 Long Rod 800 small block needs Pistons about the exact same time the old carb big block motors did.

What do I do different ?

#1 - I went back to a 136mm center to center custom rod - ( less piston side loading into the cylinder wear ) less chance of pushing them the oil barrier.

#2 - I plateau hone and polish the Nicasil bore to a mirror like finish.

So....... Rod ratio & cylinder finish in a POLARIS EFI is vital to long engine life.

It's still not perfect...... If I would have went to a 140mm rod center to center the 800 small block would be just about indestructible.

Dan
 
Last edited:
Premium Features