2012 piston pics & video

[CROW]

With over 4,000 miles on my '12, I decided I should look at the top end this year. I bought this last year, it was a former rental. I assume it's not the original top. The clunk is what concerns me.

 

[CROW]

https://vimeo.com/103641600
https://vimeo.com/103641614

 

[snowmobiler]

its sounds ok to me?

 

[geo]

Not really any point at guessing at this point is there? Especially with the '12's history of skirts failing.

It may be the pic (1st one) but I would take it apart to measure if I saw that piston top (looks like det particles from this vantage point). Det will collapse a piston quick.

Then I'd try to figure out why before next ride if it is as pictured.

The shined up wear spot is at the port for the exhaust gas to the valve. I have seen this on many Pros now including my original pistons.
I chamfered the ports different before the new pistons and just looked in when installing a different pipe and after 1000 miles on the new pistons fitted tight does not show this.
Not common practise anymore and kinda technical and many ignore it and are fine but if you have a 2 stroke specialist (someone who has been around since liners were normal or does actual porting) near by you may like to take the barrel and pistons to them for opinion, measure and hone.

 

[GoBigParts]

Ptetty good for 4000. My dealer showed me a number of 800 pistons where the ring groove begins to open up until it breaks off.