LeakDown results- post em up

[Prayn4snow]

I repeated the leak down test on my 850 with a different test kit and ended up with the same results as my more expensive tester. The cheaper one is an OTC 5609 on line.
My tests using 100psi at TDC was 98 which = 2% leak down. I only use Polaris Extreme oil. Test done at room temp and motor cooled to touch after running. If you haven't done one before I would use something soft (like a Q-tip) to find TDC top dead center after pulling your spark plugs. Of course do 1 cylinder at a time, but you will need something or someone to hold the primary clutch from spinning once you add air pressure. Do not damage your clutch!! A clutch tool from SLP works great or you could be careful and use a wooden broom handle. Once I find TDC I put a sharpie mark on the end of the clutch bolt so I know it hasn't rotated under pressure.
1st pic is gauge hooked up before air pressure added.
2nd pic is with 100psi shown on left gauge, right gauge is how much the cylinder is holding.
3rd is Operating instructions. At the bottom you will see that my cylinder at 100psi held 98psi which translates to 2 percentage of leakage.
4th Cheap kit that can be ordered on line for cheap at less than 1/5th of my "good brand" that showed the same results.
5th OTC cheap compression tester. Didn't read as high as my higher $ tester, but it was consistent on several cylinders I tested. When I test compression with any tester, I only compare prior readings from the same tester for this reason. What is more important to me it the pressure differential between cylinders. For example if one is 130psi, and the next one is 115psi you have a problem.
6th is the cheap compression test kit part # 5606
7th is my reference above about marking the clutch bolt once you've found TDC.
Hope this helps.

 

[Sheer]

This whole thing seems like a giant waste of time to me... unless you have a prob with your sled, low power, runability.... why bother... its not known for top end issues for 1, 2, if you suspect something bring it to dealer and get them to do it, you got a 4 year warrenty why not use it??? 3, if you dont trust the dealer or think the diag is wrong yea shure maby than do it... aside from that if your want to know where your engine sits than shure go ahead.. but i got better things to do than leakdown test a brand new sled.... maby i will go check the amp draw in the heating element of my brand new coffee maker just so i can keep tabs on it till it goes off warrenty

 

[Prayn4snow]

This whole thing seems like a giant waste of time to me... unless you have a prob with your sled, low power, runability.... why bother... its not known for top end issues for 1, 2, if you suspect something bring it to dealer and get them to do it, you got a 4 year warrenty why not use it??? 3, if you dont trust the dealer or think the diag is wrong yea shure maby than do it... aside from that if your want to know where your engine sits than shure go ahead.. but i got better things to do than leakdown test a brand new sled.... maby i will go check the amp draw in the heating element of my brand new coffee maker just so i can keep tabs on it till it goes off warrenty

Sheer, I total understand your point. "Most" people will never do this or need to do it. The OP wanted people that did this test to simply post results. There were comments from some that wanted to know the how to do it and what to use. I simply like to help people make up their own minds if a product (bumpers, pipes, tracks, gearing, big bore, clutching, piston durability kits, turbo's etc) are right for them. Im the type that does these tests regardless for my own 2 cents. I have a log of base lines for each sled and race car I build. I just twisted the crank a year ago on a ProCharged (Intercooled supercharger) 70 Corvette for example. When you risk smoking a $15,000 motor you tend to look at the little things including ultra balancing rotating items. In this case the manufacture of the crank rated it to over 1000hp. I made 1000 my goal, and with enough boost and the right bolt on components and machining this is now a reachable goal. Because I documented everything the crank manufacture had to admit they messed up.
These are useful tools, and 4 years of warranty is rare in snowmobiling. These test are helpful for the 1 year warranty baseline, diagnosis, buying used sleds (or any engine). Its quick, easy, fairly cheap (some parts stores will rent you the tools for a day even) and for some gives peace of mind. Others are weirdos with ADD like me, I don't know, my teacher said I was special but my mom had me tested . Enjoy the snow and the sled

 

[Big10inch]

This whole thing seems like a giant waste of time to me... unless you have a prob with your sled, low power, runability.... why bother... its not known for top end issues for 1,

The advice to do a leak down test was given in the context of "IF" you are having issues. Some may have the tools and baseline, or are just curious. Maybe they do not consider it a waste of time like you...

"not known for top end issues...." and you know this how? First season, new motor, there is no way you can give it a good rep without some time under its belt. After a couple of seasons on the snow with lots of user miles you may be able to make that statement but at this point you are just hoping that is true, because nobody really knows yet.

2, if you suspect something bring it to dealer and get them to do it, you got a 4 year warrenty why not use it??? 3, if you dont trust the dealer or think the diag is wrong yea shure maby than do it... aside from that if your want to know where your engine sits than shure go ahead.. but i got better things to do than leakdown test a brand new sled....

Because sometimes the dealer is a considerable drive... because a lot of dealers have terrible service departments... because you just want the knowledge of a healthy engine before you go into the back country... because warranty work takes time away from riding...

Lots of reasons why I think...

maby i will go check the amp draw in the heating element of my brand new coffee maker just so i can keep tabs on it till it goes off warrenty

Why? are the crank bearings failing on your brand of coffee maker too? Contrary to what you want to believe there are a substantial number of new sleds going down. That is why some are interested in testing them. You don't think so, I get it. Good Luck with your sled but maybe a little "to each his own" is applicable here...

 

[Sheer]

Why? are the crank bearings failing on your brand of coffee maker too? Contrary to what you want to believe there are a substantial number of new sleds going down. That is why some are interested in testing them. You don't think so, I get it. Good Luck with your sled but maybe a little "to each his own" is applicable here...

Sorry but i believe my dealer showing me with my own eyes 2 that let go out of all they sold, polaris sending me a letter and saying its 2%, (ob par with every other brand by the way) and myself owning one...
Ontop of everyone else on here.. no i dont believe the biggest polaris troll on here, sorry u had bad luck wuth them but you dont need to bash every polaris thread there is..

 

[Timbre]

Definitely the BIGGEST troll on this site - by far!! No self-control at all. Nothing he says has any value at all, and adds NOTHING worthwhile or constructive to the conversation!

Surely there is someone who might enjoy his "contributions" on another part of this forum (cat section) . . .or on another site altogether, would be best case scenario.

I have found that the "ignore" feature works VERY well to keep that little "bugger" away

 

[minus40]

Have not been able to ride much but a slight improvement At 30 hours, 4% leak both sides

 

[Big10inch]

Sorry but i believe my dealer showing me with my own eyes 2 that let go out of all they sold, polaris sending me a letter and saying its 2%, (ob par with every other brand by the way) and myself owning one...
Ontop of everyone else on here.. no i dont believe the biggest polaris troll on here, sorry u had bad luck wuth them but you dont need to bash every polaris thread there is..

You clowns and your "trolling" accusations need to chill. What I posted wasn't trolling, not even in the least. Just because I post in the Polaris section does not make it trolling...

Posting that they do not have problems is more apt to be trolling than anything. The poll is up to 53 dead 850s this morning, I bet those guys do not think I am trolling because they are living the nightmare... Believe what you want but there is more evidence on my side than yours. If there was no problem, this thread wouldn't exist, and polaris would not be issuing statements, extending warranties or any of that. Enjoy your denial.

I do not bash every polaris thread there is, not even close... You however have started coming to the Cat section and trolling there I see, the pot calling the kettle black maybe?

So if you do not like reading my posts, do like Timbre and put me on ignore. This witch hunt to try and keep me from posting using silly propoganda, calling me a troll is pathetic. I know you abhor the truth, I get it, more comfortable to have you head in the sand but NONE of that was instigated by me. I am just participating in the discussion and I used to be sorry it hurt your feelings but I have gotten over that...

 

[willjogervais]

...

 

[Sheer]

You clowns and your "trolling" accusations need to chill. What I posted wasn't trolling, not even in the least. Just because I post in the Polaris section does not make it trolling...

Posting that they do not have problems is more apt to be trolling than anything. The poll is up to 53 dead 850s this morning, I bet those guys do not think I am trolling because they are living the nightmare... Believe what you want but there is more evidence on my side than yours. If there was no problem, this thread wouldn't exist, and polaris would not be issuing statements, extending warranties or any of that. Enjoy your denial.

I do not bash every polaris thread there is, not even close... You however have started coming to the Cat section and trolling there I see, the pot calling the kettle black maybe?

So if you do not like reading my posts, do like Timbre and put me on ignore. This witch hunt to try and keep me from posting using silly propoganda, calling me a troll is pathetic. I know you abhor the truth, I get it, more comfortable to have you head in the sand but NONE of that was instigated by me. I am just participating in the discussion and I used to be sorry it hurt your feelings but I have gotten over that...

Do you really think that poll is accurate? You dont think every person who voted really even owns a 850?? You got to be kidding..And you think i got my head in the sand?? Come on man im not saying there hasent been a few dead ones, is there there a problum? I dought it... what really happend is they f-ed up putting them together they changed the way they assemble them, and its fixed... but we got people like u saying oh wow what a pos motor... theres also been a few dead cats and doos but why theres such a big deal about the pros i dont get it...

"This witch hunt to try and keep me from posting using silly propoganda" you sound like trump bud...

"Posting that they do not have problems" have i ever said that? Mine hasent had any... i havent said this engine is 100% prob free..

"Believe what you want but there is more evidence on my side than yours" no there is not, i have my experence, a publicly traded company (polaris) makeing it illigal to pourpsely mislead the public and investors into the reliablity of the engine, ontop of the dealers, you got a snowest fourm poll? Ok..

 

[Big10inch]

Yes, I think the poll is accurate. Do you have any sort of proof that people have been lying in the poll? I didn't think so...

You think people are tainting the results because they are jealous... I think most of us are just tired of Polaris lies. This was supposed to be the best sled motor ever and so far it has come up short. Those of us unhappy with this turn of events in many cases were looking to come back to Polaris but refuse to keep being beta testers for their products, ie; last time they updated the engine I bought one and I was one of those that they screwed...

I just honestly wish they could get it right, I really do because I would be a customer again if they did. I REALLY like the machine, I just can not chance the iffy quality anymore.

Even if half of the respondents lied in the poll, you still have 25-30 dead machines just listed here which is somewhere between 5 and 10 times as many failures as the competition. Glad yours is running well, hope it stays that way for you. I suspect a bunch more of you will be choking down crow before too long though...

 

[NHRoadking]

Do you really think that poll is accurate? You dont think every person who voted really even owns a 850?? You got to be kidding..And you think i got my head in the sand?? Come on man im not saying there hasent been a few dead ones, is there there a problum? I dought it... what really happend is they f-ed up putting them together they changed the way they assemble them, and its fixed... but we got people like u saying oh wow what a pos motor... theres also been a few dead cats and doos but why theres such a big deal about the pros i dont get it...

"This witch hunt to try and keep me from posting using silly propoganda" you sound like trump bud...

"Posting that they do not have problems" have i ever said that? Mine hasent had any... i havent said this engine is 100% prob free..

"Believe what you want but there is more evidence on my side than yours" no there is not, i have my experence, a publicly traded company (polaris) makeing it illigal to pourpsely mislead the public and investors into the reliablity of the engine, ontop of the dealers, you got a snowest fourm poll? Ok..

Polaris would not be the first company to mislead the public (recent example: VW diesel scandal).

Regardless, here's hoping that issues with the Polaris 840 get resolved soon. I definitely am interested in one provided the reliability is there.

As far as poll results, there are a guide at best. Never 100% accurate (recent example: polls before 2016 election). They can be a clue as to public perception and if the perception is that the new motor has issues that perception has as much impact as the reality. That's human nature.

 

[Timbre]

As far as poll results, there are a guide at best. Never 100% accurate

Yah, and combine that with the trolls, and those saying "bad engine" who also had something to sell you. The hype of "mass engine failure" has not matched the reality . .. not even remotely close!

 

[TRS]

Leak down results.
12-22-18 mag 2% pto 2% out of the box

3-5-19. mag1%. pto2%

Just shy of 400 miles. Looks like I have a good one. Boys will keep riding it.

 

[tdbaugha]

I have the OTC tester and have never got good numbers. 1 ride on a brand new top end and I'm getting 4% & 5%. Compression test is 128psi both cylinders though.

Prior to the first rebuild I was seeing 7% & 8%. It was running 250-300 RPM shy of my buddies 850. Oil line popped off and it was tore down. Here were the pistons:

 

[sledhead_24_7]

I have the OTC tester and have never got good numbers. 1 ride on a brand new top end and I'm getting 4% & 5%. Compression test is 128psi both cylinders though.



Prior to the first rebuild I was seeing 7% & 8%. It was running 250-300 RPM shy of my buddies 850. Oil line popped off and it was tore down. Here were the pistons:

Nice pictures.

Totally sucks that happened though.

 

[Matte Murder]

Sledhead is the black stuff on the piston the stock coating wearing off or carbon from blow by? Did the shop replace the cylinders or hone them or anything or just put new pistons in?

 

[willjogervais]

tdbaugha- yikes... This is my biggest concern from this motor. How long did it take them to get it fixed up for you? Any issues from poo?

 

[tdbaugha]

Long story. First dealer wanted to put it back together as-is. Finally got a new set of pistons, crank, and case from them. Picked it up 17 days after I dropped it off, rode it around my yard, and then started going through it and found this:

2 bolts were broke off in the case and 4 had pulled the threads. Only 1 was fine which was the one that needed to be installed while the engine was in the chassis. So then I took it to Kurts in Seeley to get fixed AGAIN. Got it back this past Sunday. Dropped it off at the first dealer Jan 25th.

 

[Prayn4snow]

That’s pretty poor quality control on that Dealership’s part. As I travel across the country each year snowmobiling and talking to dealerships ( seems I’m averaging a lower a arm in each state). They are having a hard time finding and keeping qualified, highly trained mechanics and end up paying low wages to less qualified mechanics. Sadly many that are turning wrenches are not mechanics at all but in training or helpers. Don’t get me wrong. There are a number of dealerships that do you have highly trained, motivated and “certified” mechanics. I’ve had some bad experiences myself this year that cost me quite a bit of premium riding time. I don’t want to turn this into a bashing thread but if you have good experiences with a dealership service or highly trained mechanics we should start a new post listing them. This goes for all brands as I am in equal opportunity snowmobiler I have a number of different brands in my garage except for Yamaha, my trailer does have load capacity restrictions