BigTimeFarmer
New member
first off, it's a polaris 600 and it's not mine so thank god it's not my problem but i was still intrigued. i've never seen a piston look like that before. he figures the ring ends broke off and wore those grooves in the piston. had to be something. i figured everyone likes pictures of wrecked pistons as long as they're not your own.
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![IMG00036-20110102-1850 [800x600].jpg](/data/attachments/20/20715-ace01add7dd43b3fd4c60ed78ee0f162.jpg?hash=rOAa3X3UOz)
![IMG00037-20110102-1851 [800x600].jpg](/data/attachments/20/20716-f616c9b9b91e5e999c4b5cd1bb787b8d.jpg?hash=9hbJubkeXp)
![IMG00038-20110102-1851 [800x600].jpg](/data/attachments/20/20717-533fa7d42041f3a86b482de7f5bd4b26.jpg?hash=Uz-n1CBB86)
BigTimeFarmer said:
If it's a monoplock triple check to make sure the wrist pin C clips are still in place. They extended the warranty for that problem and after a long drawnout battle I finally settled with machining/parts costs and lawyer's fees.
It was the reason I switched to Yamaha.
no1chevyboy
New member
what do cylinders look like? kinda strange but the other piston looks like it has the same witness mark in the same place
Dansvan
New member
Looks like the pin that keeps the rings from rotating came out.
BigTimeFarmer
New member
didn't see the cylinders but the good side looked ok i guess. we also noticed the identical wear on the front of the pistons. the pistons are stock he said they put new rings on it at the begining of last season. they must've screwed something up. could this have been caused by a bad end gap? rings put in upside down?
no1chevyboy
New member
is that the pin location on both sides? could have been to tight a ring gap or defective rings? were cylinders in spec. a tight ring gap and a worn cylinder may cause that.
Dansvan said:
ya, both of them.
it also looks like the cheaper spi pistons as well, could very well be the reason, you get what you pay for.
BigTimeFarmer
New member
mrviper700 said:
as far as i know they are oem pistons, they were never removed just reringed
BigTimeFarmer
New member
no1chevyboy said:
that's my guess.
looks like butt pins worked their way out
horkn
New member
Looks like this was easily preventable, but steps were skipped and this happened.
This can happen to any motor if corners are cut.
This can happen to any motor if corners are cut.
opsled
Active member
The ragged edge on the crown of that piston leads me to think it had gotten very hot at some point in it's life. Those pins are steel, piston aluminum. The pins are pressed in (locktight too?) and a heat cycle that was beyond safe limits could have disrupted the quality of that pin fit??
Just a thought,
opsled
Just a thought,
opsled
ottawaair
New member
mrviper700 said:
Lost the pins on a couple spi's before, would never use them again. Happened in about 100 miles of riding.
BigTimeFarmer
New member
The piston pins are intact. Could an out of spec end gap be the culprit? Obviously they didn't put her together right.
no1chevyboy
New member
i think to tight might do that.or may be deffective rings out of round at ends or wrong step for pin? just seems odd that both pistons have witness marks at the ring gap.
maybe they forgot to lube the rings with some oil during installation. when installing the cylinders.
Last edited:
possibly air bubble in the oil line. got it too hot.
BigTimeFarmer
New member
no1chevyboy said:
I know. I think he should consider the other side is shot too. The real funny thing is that it lasted so long before it finally puked. They did the ring job last year.
no1chevyboy
New member
looking at the pics again there is allot of blow by cylinders may be out of roundor hour glassed?