Jeremybeiler
New member
Hey fellows, anyone with a good guess what caused this piston to blow ?
pictures? type/model of sled would help as well.
Jeremybeiler
New member
wow.... brothers was similar to that but not as bad as yours. looks like the needle bearing in the connecting rod let go and made it up onto the piston or other debris went through. looks like it was on the lean side too. if it is an unmolested sled (oe) they had a lean spot in the mid range when sustained cruzing at that speed. the needles needed to be raised help with this. most guys never blew them as when the sled was passed to the gf/wife, they held the throttle at those speeds while the guys would be way more agressive and not stay in that spot long enough for it to be an issue. check the carb boots for a leak and check the y pipe as they are known to crack witch can cause lean issues.
Definately leaned out. Personally I have never seen an oem wrist pin bearing fail unless unlubricated. Bad gas, old gas, alcohol fuel(ethanol), or water in there. Mag side looks like it was melting as well unless its a photo flash. Your hand is in the way of the pto side