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  1. #1
    I'D RATHER SWEAT THAN SHIVER hyoctane23's Avatar
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    1998 Polaris Pro 785 rebuild

    Hey guys...long time no talk. I've been pretty busy with work and some personal stuff that happened last year so I have not been on here in a long time. Summer is fast approaching and I have some things that both skis need before they hit the water again. My '98 has low compression so it looks like a ring job is in order. It has not been pulling the RPM and speed lately and I think that is due to the low compression. I'm only getting about 110 PSI on all 3 cylinders and that is with an ADA head.

    So first things first, I need to get a new set of rings. I'm thinking that the pistons are still good so I will reuse those. Should I go on and use 750 rings instead of 785??

    Also, my pump stator bearings are shot so those need to be redone.


  2. #2
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    Welcome back stranger.

    What pistons are in it now? OEM 785 I presume?

    The guys have the bearing part #'s and seal part #'s posted in the tech section. Might as well get a couple sets from a bearing warehouse since you seem to go through them alot.

  3. #3
    I'D RATHER SWEAT THAN SHIVER hyoctane23's Avatar
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    Thanks, xlint!! Glad to be back!!!! They are the stockers.

    I think the bearings are going out because those seals that come with the kits are pieces of crap!!! I dunno, maybe I'm doing something wrong

  4. #4
    Click avatar for tech links/info, donation request K447's Avatar
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    Quote Originally Posted by hyoctane23 View Post
    ...I think the bearings are going out because those seals that come with the kits are pieces of crap!!!

    I dunno, maybe I'm doing something wrong
    There was another member who had a stator that went through stub shaft bearings in a hurry. Turned out the stator itself was not properly machined at the factory and the stub shaft bearings were not sitting true when set into the stator. I believe he ended up setting that stator aside and getting another one, and that seemed to fix the problem.

    Are the bearings rusting to death, or grinding themselves to death before the rust sets in?

  5. #5
    bowsniper's Avatar
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    Might want to warm up the stator to 200 degrees in the oven with out the seals in it of course, then freeze the bearngs before installation so that they "fall " right in and prevent any chance of binding or alignment.

    Don't forget to put the spacer in first before the last bearing goes in!

  6. #6
    I'D RATHER SWEAT THAN SHIVER hyoctane23's Avatar
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    Quote Originally Posted by bowsniper View Post
    Might want to warm up the stator to 200 degrees in the oven with out the seals in it of course, then freeze the bearngs before installation so that they "fall " right in and prevent any chance of binding or alignment.

    Don't forget to put the spacer in first before the last bearing goes in!
    Yessir, that is exactly how I do it!

    K, what is happening is that stupid oil seal keeps breaking....like the garter spring keeps falling off so water starts getting into the bearings and rusts them out. Do they make any sort of like double spring seals??

  7. #7
    Click avatar for tech links/info, donation request K447's Avatar
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    Quote Originally Posted by hyoctane23 View Post
    ... oil seal keeps breaking....like the garter spring keeps falling off so water starts getting into the bearings and rusts them out...
    Were your seal springs SS, or treated/coated to resist corrosion?

    Check that the impeller stub shaft isn't bent or out of spec in some way.

    When you take the stub shaft out, are the thin sealing lips still in decent condition where they ride on the shaft?

    If you don't trust the generic seals, genuine Polaris stator seals aren't that expensive. Especially if they actually stay together better than what you are using now.

  8. #8
    skigolfnut's Avatar
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    I had a similar problem with my 1997 stock pro 785 last summer,low rpms, then good rpm's,
    I took it to Matt at Genes, I had ingested water in the center cylinder, but my stator was going out and it was real iffy, caused a lot of low rpm's sometimes running good, sometimes running crappy, I changed the stator and he did the a new piston and rings in the center cylinder and presto, back running strong,

  9. #9
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    I do not know if 750 rings will fit a 785 piston. Shoot Lugs or Jay at Sharp's a PM and see what they have to say.

  10. #10
    I'D RATHER SWEAT THAN SHIVER hyoctane23's Avatar
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