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  1. #1

    1996 xp 787 problems

    Hey, I know I posted a thread before about the same problem, but I got another question. OK, so the number one cylinder is filling up with oil probably a crank seal. Seadoo mechanic told me the 787 doesn't have crank seals. He said that the cases have shifted and just need lined back up. Ski cranks over real smooth though and doesn't have very many hours on it. I did a top end last winter and it ran great the following summer. Now I can't keep it running or even start most of the time. Has anyone done crank seals in these motors? Will I need to split the cases? Will a block off plate eliminate this problem? The help is much appreciated
    Thanks Austin

  2. #2
    96XPSS's Avatar
    Join Date
    Feb 2006
    Warner Robins, GA Home of the 2007 All-Star Little League World Champions!
    Hey Austin, welcome to GH.

    The cases don't shift, the original 518 used to seal the case halves breaks down and leaks oil into the cavities (intake area) of the cases. Get someone else to do it, as that guy is an idiot. There are two crank seals, but they very seldom fail. Use Three Bond 1211 as the sealer, and it will never leak again.

  3. #3
    i totally agree. that guy is a idiot. crank seals rarely go bad. the typical problems with bad seals will be a big lack in power and will smoke alot, being that there is less secondary compression under the piston, that helps draw the oil and fuel into the cylinder. be sure you dont have a firing issue aswell. loctite 5910 is what is used from the factory. buy yourself a service manual it can help out with diagnosis and the right solvents or bonding agents to use. you'll pay that idiot a hole lot more than the manual will cost you.

  4. #4
    Well I never had any intention of taking it for him to work on, I just went up there to order some seals and gasket kit because I was just going to tear it down to see if I could find anything wrong with it and they pretty much told there wasn't any seals. Just checking to see if anyone else had run into this problem with the 1996 787 motor. If not crank seals then what? Guess I will just have to breank down and buy a manual

  5. #5
    Sly Fox DKFox's Avatar
    Join Date
    Feb 2009
    Huntsville, Alabama
    Download the shop manual from here:

  6. #6
    Hey thanks for the shop manual.

  7. #7
    steach's Avatar
    Join Date
    Dec 2005
    Rock Tavern, NY
    My guess is the rotory valve seal. The oil bath oil entering the intake manifold/ports. This is easy to see if you have the line disconnected and looped.

  8. #8
    96XPSS's Avatar
    Join Date
    Feb 2006
    Warner Robins, GA Home of the 2007 All-Star Little League World Champions!
    Quote Originally Posted by austind View Post
    If not crank seals then what?
    How about you read my first post and answer your question?

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