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'15 Axys 800 Pistons W/ 3500 miles

Lenn Johnson

Active Member
Messages
111
Age
61
Location
Pembroke NH
15 Axys 800 Pistons.jpg

These are out of a '15 800 Axys Switchback. Around 3500 Miles. Always used Polaris oil. Pulled them to do the durability kit. What's with the deep scratches?
 
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Here's the old piston next to the durability kit piston. Notice the oiling holes in the new piston where the grooves are in the old piston?
Dans Pistons.jpg
 
With the scratches in the pistons, how did the nic coating in the cylinders look?
Was there any collapsing of the skirts?
 
Are there similar ones on the other side of piston
 
With the scratches in the pistons, how did the nic coating in the cylinders look?
Was there any collapsing of the skirts?
This sled belongs to my cousin. The nickel-silicon plating looked good except for where the groove was...showed a little wear there. Honed it well and now everything looks good. These grooves/scratches were only on one side of the piston. The skirts looked fine.
 
Am I the only one thinking, if that sled was rode aggressive trail/ hard as possible, that the pistons look pretty good?

Or are my expectations of Poo pistons to low?
 
Looks like the beginning of 4 corner seizure? Swollen piston contacted cylinder wall.

Tons of possible reasons.

Maybe ran hard before warm-up once?

Maybe ran a little lean for whatever reason? (sensor issue, injector issue, ethanol issue, air leak?)

One thing I learned recently is that ethanol fuel can be mixed sloppy. E10 can be e12 or e8.

Imagine a guy running in non ethanol mode, getting e12 gas and running a little hard before things warm up completely.

Pistons swell, oil barrier breaks down, scoring.
 
That's kinda what I was looking for. I was was thinking a 4 corner seizure start. Poo has a cold engine safety feature built in for 17. Possible they east at enough to feel that protection was needed ? Hard to say. Personally I like to put a new top end in every other year or def. by 3500-4000 miles. On any 2 stroke of any brand. I'm fat and ride em hard. So I understand they wear faster for me. On the other hand my father is in more danger of fouling a plug than using up the engine. Lol
 
That's kinda what I was looking for. I was was thinking a 4 corner seizure start. Poo has a cold engine safety feature built in for 17. Possible they east at enough to feel that protection was needed ? Hard to say. Personally I like to put a new top end in every other year or def. by 3500-4000 miles. On any 2 stroke of any brand. I'm fat and ride em hard. So I understand they wear faster for me. On the other hand my father is in more danger of fouling a plug than using up the engine. Lol

Yeah. I agree.
 
Here's the old piston next to the durability kit piston. Notice the oiling holes in the new piston where the grooves are in the old piston?View attachment 1725
Question
Who's wosseners pistons are those ?

If you still have them out. Can you measure 3/4" from bottom of skirt and above top ring for me ? Just wannna know how much they taper ?
Should be anywhere from 0.014"-0.020"
 
Am I the only one thinking, if that sled was rode aggressive trail/ hard as possible, that the pistons look pretty good?

Or are my expectations of Poo pistons to low?

It was rode aggressively but always warmed up 1st. Not sure what caused it. He did have some det issues with his SSI pipe mod. He's running a PC-V. I'm not sure who's durability kit he's using, I'll have to ask. What's interesting is the groove/scratches are in the same spot where the replacement pistons have holes drilled.
 
Question
Who's wosseners pistons are those ?

If you still have them out. Can you measure 3/4" from bottom of skirt and above top ring for me ? Just wannna know how much they taper ?
Should be anywhere from 0.014"-0.020"

New pistons are already back in.
 
I am with racerdave, looks like the exhaust valve is scuffing the piston, better fix that or it will occure again. Give Indy Dan a call, he can fix that for you, I have done all of my machines starting with my 07 700 Dragon and 2 sons have 2012 and 2015 800 PRO RMKs and my 11 PRO RMK 800 and daughter in law 800 Dragon so I dont expect to have the pistons and exhaust valves come together any time soon. This is a problem that Polaris does not even acknowledge is there, but I KNow for sure it causes large pieces to become smaller pieces just before the engine fails!!
gtwitch in wyoming
 


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