Piston Starting to Go? Video

[GoBigParts]

Looking through the exhaust port Mag side. PTO side much more work to get out.

Look at the top ring movement. Too me it looks like the to of the piston is starting to expand making the ring slot really loose. Around 2200. Never opened the motor up, which you shouldn't have to.

http://www.YOUtube.com/watch?v=ph75LVf0awU

 

[mtncat1]

just pull it apart,and put in a set of rktechs direct replacment pistons at 2200 miles its due plus you can check the cylinder skirts at the same time.this is a very easy to work on chasis and motor should only take a few hrs to complete

 

[GoBigParts]

I would love to but it is covered under warranty so can get it fixed for free for the remainder of this year plus 2 more years.

 

[AdrenalineAddict]

If your piston happens to be tipped or rocked to the intake side you will see what might appear to be an oversized ring land that may or may not be. I would be more concerned with what the rest of that piston looks like from the ring land down. My mag side piston was a scored up mess at 2,300 miles, it obviously needed attention. Polaris warrantied my top end but would only cover the repair when I could document a compression difference between the good and bad cylinder, things got pretty ragged.

 

[milehighassassin]

Looks fine to me. There needs to be play in the ring groove.


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[cascadesnowjunky]

Looks normal to me also. There has to be play to allow the ring to expand and retract length ways without binding. The only thing I see is the shiny vertical spot that goes through the ring land, looks like it started to scuff or roll aluminum. It is very hard to tell with video though.

 

[Vertical Asshauler]

It does look like a little skuff on the piston. Would be nice to see the rest of the piston skirt to see how bad it really is.

 

[GoBigParts]

Yes, I know a little play is normal but I could stick a dowl in there and move the gap to the top side of the ring or the bottom. In other words I could move the ring. After the dealer showed me other 800 CFI pistons that went they all seem to have a very large gap on the exhaust side top ring to the point that some the top broke right out from the ring groove up. I will post a pic.

 

[GoBigParts]

Here is a picture of the piston.

 

[knifedge]

--Look at the piston below the ring set. If it it dark and burnt looking, your getting a ton of blowby and loosing power. It looked like your rings were dark also. Your tolerances are probably also out. This motor is probably nearing the end of its short, useful life.

--Maybe get a replacement piston set installed and then later install a RKT set and sell the OEM set. Better yet, just flog that motor till it blows(which could be any time)(try to blow out the crankcases also so warranty covers a longblock) and get a new 2013 motor installed.

 

[GoBigParts]

I did look below ring and didnt see any scratches but some blow by. The good thing about catching it early is they can fix in a few days without loosing riding time. If it blows bad then I will be out a couple of weeks while Polaris looks at it.


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[Reg2view]

Hate to say it, but riding it hard till it blows under warranty is the best solution for most - owner gets a new motor, Poo gets the message that their motor service life stinks in the way they understand best - $$$. To do this well, one must also have a backup sled. And a warranty, of course.

 

[AndrettiDog]

Did you pull the head to see the top of pistons yet? I had some slack in my piston as well on my 2011. It's still running strong with no issues.

 

[geo]

Ya but what if you ride it and it doesn`t blow? Would that piss you off?

Looks like you have had a little chamfer issue since new.

 

[KON]

I did look below ring and didnt see any scratches but some blow by. The good thing about catching it early is they can fix in a few days without loosing riding time. If it blows bad then I will be out a couple of weeks while Polaris looks at it.


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I will think that when the enginge has operating temperature that slack will be gone and no worries.. It is the same on new wisecos w/cold enginge..

 

[GoBigParts]

Hate to say it, but riding it hard till it blows under warranty is the best solution for most - owner gets a new motor, Poo gets the message that their motor service life stinks in the way they understand best - $$$. To do this well, one must also have a backup sled. And a warranty, of course.

The question is, the new motor any better than mine with new pistons and rings. Have they changed anything to fix the problems I doubt it. I new mine if any would go knowing others have had problems with these motors. Seems mine always had more issues than others, no matter what I own. LOL.

 

[GoBigParts]

Update: I did get the factory pistons and rings replaced under my extended warranty. $50 (deductable) for a new top end rebuild is not bad. Have the parts here if anyone would like to see pictures. From the looks of it the rings are flaked some. The ring groove is more open on the exhaust side. The rest of the piston looks fine. So the sled never went down. At 2400 miles started to feel not as strong as when new and lost a 100 or so RPM. Interesting to see if I can get another 2400 miles.

 

[milehighassassin]

Post up the pics.


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[knoba]

rebuild

Did the shop re-hone the cylinders? I think alot of these dealers put new pistons in without re-honing the cylinders!

 

[wellfed777]

2400 miles on a 2 stroke snowmobile engine !

not defending polaris but any 2 stroke wants pistons by 2400
glad you got her back up quick