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  1. #1
    imp0ster's Avatar
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    How does the carbon seal and PTO carrier bearing work

    Now that I have it all apart I see the shaft doesn't even touch the carbon seal. It looks like water is kept out by the pressure put on it by the top hat. If the top hat slides forward I sink?

    Also, how does the carrier bearing keep oil in? There's no real seal where the actual bearing is, just the two o rings where the shaft slides through.


  2. #2
    Sayers's Avatar
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    Now that I have it all apart I see the shaft doesn't even touch the carbon seal. It looks like water is kept out by the pressure put on it by the top hat. If the top hat slides forward I sink?
    CORRECT. The C clip stops the hat from sliding forward which is why you should inspect for wear and ensure you reinstall properly.


    Also, how does the carrier bearing keep oil in? There's no real seal where the actual bearing is, just the two o rings where the shaft slides through.
    ??? O rings seal bearing @ shaft, rubber boot clamps to bearing and PTO.

  3. #3
    skigolfnut's Avatar
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    the oil in front of the shaft is really not under much pressure, it lubes the front of the shaft, the carrier bearing from what I can tell has such a close tolerance and a tight fit, that it would be difficult for oil to seep by,

    The top hat is held in place by the C clip, if the C-clip groove gets worn and it comes loose you sink,
    The pressure of the accordian boot applies enough pressure for the carbon ring to keep out any water while it is spinning, when the accordian boot gets old, it starts to shrink and does not put as much pressure on the top hat and you start to get more cavitation on dead stop starts, from air sucking past the seal,

  4. #4
    JT jpt7779's Avatar
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    Other factors are engine alignment, carbon ring wear, and bellows wear. You can now see that if the engine alignment with the pump is off just a little, it will cause the floating ring(hat) to be miss-aligned with the carbon ring and not have a good seal. The engine must also be aligned correctly fore and aft. Too far forward, it doesn't put enough pressure on the bellows and carbon ring. Too far aft and it puts too much pressure and causes excess wear. The bellows get stiff and shrinks in size over time causing leaking also.

    In the 2011 Shop Manual and newer, they started to put this "for / aft (longitudinal) measurement" into the alignment process. There is only 3mm of play in this setting, so it is very critical!

  5. #5
    imp0ster's Avatar
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    The accordian is a VERY tough unit. I saw no need to replace that. I used Ultra Grey around the new carbon seal and the through hull for the accordian boot. Ultra black around the carrier bearing and on the PTO outlet. The carrier bearing looks squirrely to me and I think they should have used ceramic bearings instead of something that rusts(the outside of mine is rusted).

  6. #6
    imp0ster's Avatar
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    Guess I'm just a little weirded out that SeaDoo left the fate of the ski up to "assumed' pressure with the top hat. They assume the pressure will be there.

  7. #7
    Sayers's Avatar
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    Quote Originally Posted by imp0ster View Post
    The accordian is a VERY tough unit. I saw no need to replace that. I used Ultra Grey around the new carbon seal and the through hull for the accordian boot. Ultra black around the carrier bearing and on the PTO outlet. The carrier bearing looks squirrely to me and I think they should have used ceramic bearings instead of something that rusts(the outside of mine is rusted).
    Quote Originally Posted by imp0ster View Post
    Guess I'm just a little weirded out that SeaDoo left the fate of the ski up to "assumed' pressure with the top hat. They assume the pressure will be there.
    All that sealant is not needed. Make sure the PTO bearing is pulled back and clips onto the shaft properly.

  8. #8
    imp0ster's Avatar
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    Quote Originally Posted by Sayers View Post
    Quote Originally Posted by imp0ster View Post
    The accordian is a VERY tough unit. I saw no need to replace that. I used Ultra Grey around the new carbon seal and the through hull for the accordian boot. Ultra black around the carrier bearing and on the PTO outlet. The carrier bearing looks squirrely to me and I think they should have used ceramic bearings instead of something that rusts(the outside of mine is rusted).
    Quote Originally Posted by imp0ster View Post
    Guess I'm just a little weirded out that SeaDoo left the fate of the ski up to "assumed' pressure with the top hat. They assume the pressure will be there.
    All that sealant is not needed. Make sure the PTO bearing is pulled back and clips onto the shaft properly.
    I used RTV like that due to a ton of reading. Snow and Skoeep agreed on that and they seem to be on top of their Doo game. Better safe than sorry. Yeah I read about the telltale groove Reading is good.

  9. #9
    JT jpt7779's Avatar
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    How does the carbon seal and PTO carrier bearing work

    Quote Originally Posted by imp0ster View Post
    The accordian is a VERY tough unit. I saw no need to replace that. I used Ultra Grey around the new carbon seal and the through hull for the accordian boot. Ultra black around the carrier bearing and on the PTO outlet. The carrier bearing looks squirrely to me and I think they should have used ceramic bearings instead of something that rusts(the outside of mine is rusted).
    Yes it is tough but, when I fixed my alignment, I found as many others have that the original bellows shrunk 1/4" in length over the years compared to a new one!

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