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  1. #1

    I need help reading piston damage.

    The pictures attached are from the mag side of a 787. I just want to be sure as it looks like a pin failed allowing the ring to rotate to the exhaust. I just need a second opinion before I reassemble the top end.
    Click image for larger version. 

Name:	Piston mag side sm.jpg 
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ID:	248244Click image for larger version. 

Name:	Piston Mag side 02 sm.jpg 
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Size:	118.4 KB 
ID:	248245

  2. #2

    Join Date
    Aug 2008
    redlake ontario canada
    if your spark plug is intact the pin holding the rings is what did that.

  3. #3
    That's what I was thinking. The plug looks good.

  4. #4
    If i knew,...I wouldn't ask sea-one's Avatar
    Join Date
    Aug 2009
    Umm, in my past experience with that damage, the crank was coming apart,..........

  5. #5
    yamabro's Avatar
    Join Date
    Oct 2008
    I'd agree the last two that just came through the cranks were the problem. After a good thorough inspection of the lower, it could have been that ring pin. Good luck with the build though

  6. #6
    How do you diagnose the crank without ripping it all apart?

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