Wrist pin was too short, thus putting too much pressure on the inner part of the piston.

 

What do you mean wasn't long enough and to much slop between the c-clips.what bore?? 102mm

 

Ryan- more details on the piston please

 

Stock bore.....From what I understand there was no slop just the pin did not go across the whole piston. Thus appling more pressure to the center of the piston instead of across the whole width. A huge chunk of the piston broke off & wedged itself between the counter balancer and the top of the case. It cracked the case along with some damage to the oil pump, and taking a chunk out of the sleeve.[img]i/expressions/face-icon-small-mad.gif[/img]

 

Thats sounds a little strange to me, was it the piston skirt that broke off or the piston top around the piston ring area.

When i installed my JE piston the wrist pin it was shorter in length than the stock Yamaha wrist pin!!!!!

 

I think all the JE pins are shorter, the area throught the piston isn't as wide.

Sorry to hear about the bad luck![img]i/expressions/face-icon-small-sad.gif[/img]

 

man thats gotta suck.hope you get it running soon again,goodluck!!

 

"Thats sounds a little strange to me, was it the piston skirt that broke off or the piston top around the piston ring area."

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Not sure

[img]i/expressions/face-icon-small-confused.gif[/img] All I kmow is I want it fixed!! JE is replacing the piston at no charge, I "JUST" have to pay for the rest of the repairs/mods!!LOL

 

The wrist pin outta my 102mm JE Piston wasn't too short. It streatched from one clip to the next no problem. Maybe its just a stock bore problem ?

 

"Maybe its just a stock bore problem"

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Was a problem...from what I understand very few went out like this (the very first ones) & since, the problem has been adressed.