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  1. #1
    Sly Fox DKFox's Avatar
    Join Date
    Feb 2009
    Huntsville, Alabama

    What is this part's function?

    See attached diagram. Bottom end of a 720 Engine. It goes under the brass rotary gear. Is is just to keep spacing between the two bearings on either side of the rotary gear? Just wondering why its even there. Its not used in the 787 engine.

    I just put a 720 engine back together and I think its rubbing slightly on the rotary shaft causing it not to turn freely. (At least when turning by hand.) Engine is still out on my work bench. Guess I'll be splitting the case again to make certain it is seated correctly.
    Click image for larger version. 

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  2. #2
    badjoka's Avatar
    Join Date
    Jun 2009
    Fairfield, CT
    thats the Retaining Ring part # 290926070 from onine parts microfiche and
    take a look here, may be of some help:


  3. #3
    Tool Bag water worx's Avatar
    Join Date
    Aug 2006
    Sunny Fla
    It is there to keep the inner seals from blowing out in case of a backfire.

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