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  1. #1
    Brian Quik draw's Avatar
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    Broken timing chain

    My 2007 RXT just spit out the timing chain. It ripped apart one of the links. Ski only has 30 hours on it. Pulled the head and doesn’t look like there’s any damage. Possibly 2 bent valves on #2. Any advise on what to look for? Someone on here told be the motor was junk and to buy a new motor. Help plz!


  2. #2
    ptscon's Avatar
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    Post pics of the piston crowns.

    If there really is no significant damage to the piston crowns than replace the bent valves and timing chain. You'll have to pull the motor and split the case to install a new chain. A bit of a project but not hard if you're handy.

    Inspect the head for valve seat and guide for any damage on the valves that got smacked.

  3. #3
    Brian Quik draw's Avatar
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  4. #4
    tiderider's Avatar
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    Most of the valves are bent. You'll have to pull the engine out and split the engine in half to replace the chain. You'll need new gaskets, head gasket, flywheel bolts (Not reusable), rocker arm bolts (Not Reusable), Connecting rod bolts (Not Reusable), Head bolts (Not Reusable), tools to lock the cam/crank for timing. valves and valve seals and a few other things including tools. Its a 8000 Rpm engine, if its not done correctly/accurately you'll spend a lot of money for parts and tools only for it to go boom within an hour.
    Last edited by tiderider; 03-19-2020 at 11:45 PM.

  5. #5
    ncdoo's Avatar
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    Yes it looks like you bent quite a few valves, you'll need to remove them all and check. Also check the valve guides .

  6. #6

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    that's a lot of carbon and oil residue for 30 hours

  7. #7
    ncdoo's Avatar
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    Quote Originally Posted by tiderider View Post
    if its not done correctly/accurately you'll spend a lot of money for parts and tools only for it to go boom within an hour.
    '

    Tiderider, I'm wondering if yours will go boom seeing how you didn't know what you were doing and you were also taking the cheap route on your rebuild? Keep us posted.
    Last edited by ncdoo; 03-21-2020 at 12:15 AM.

  8. #8
    tiderider's Avatar
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    Quote Originally Posted by ncdoo View Post
    '

    Tiderider, I'm wondering if yours will go boom seeing how you didn't know what you were doing and you were also taking the cheap route on your rebuild? Keep us posted.
    I don't know what I'm doing? Are you aware that I actually use a bore gauge and micrometer to verify clearances..
    My machinist is a specialist in high rev motorcycle engines. Though he only bores and hones for me.


    First build on CP .5mm oversized pistons with coated skirts (actually 1 of the 3 CP pistons had imperfections on it, so I won't buy CP pistons anymore, especially at $600 a pop), Molnar Connecting rods, Titanium retainers, High performance light weight valves with inconel exhaust valves and single groove keepers, ET137+4mm, ARP studs, I am surprised with the present tune and the steady 11.9 AFR at WOT 8500 Rpms. 15 hours now with no blow by and power holds steady/smooth. It must be the new added AEM340 Fuel Pump and Aeromotive 12345 filter that makes it run strong..
    Does my first rebuild engine sound like a CHEAP build?

    Second, back up engine differences in the build are Wiseco .5mm oversized skirt coated pistons instead of CP (Wiseco piston went in with ZERO Issues at only $375 a Pop) and all internal bearings are WSM instead of Stock OEM....
    Cheap as well?



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    Last edited by tiderider; 03-21-2020 at 11:03 AM.

  9. #9
    tiderider's Avatar
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    Quote Originally Posted by ncdoo View Post
    '

    Tiderider, I'm wondering if yours will go boom seeing how you didn't know what you were doing and you were also taking the cheap route on your rebuild? Keep us posted.

    I know of 3 ex seadoo owners that attempted to fix similar problems who had little mechanical hands on experience in which all 3 engines failed within a few hours.
    If your referring to why I suggest selling your damaged seadoo instead of fixing it if your not mechanically inclined..

    Heck I don't own shares in the PWC parts business as well like some in this forum may..

  10. #10
    SplishSplash's Avatar
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    Quote Originally Posted by tiderider View Post
    I know of 3 ex seadoo owners that attempted to fix similar problems who had little mechanical hands on experience in which all 3 engines failed within a few hours.
    If your referring to why I suggest selling your damaged seadoo instead of fixing it if your not mechanically inclined..

    Heck I don't own shares in the PWC parts business as well like some in this forum may..

    Your right, it not just a matter of buying parts and putting them in.
    You have to have quality tools like an accurate torque wrench to begin with and many other tools and sealants.
    A shop manual.
    A spotlessly clean work area.
    Preferable an engine stand, makes it a lot easier to work on and they are cheap at Harbour Freight. It can be done on a bench, not saying that, but the stand sure helps

    If your skilled, confident, willing to spend the time to do it right, it can be fixed. But if your not sure, then see if you can find someone that can help.

    Were all here to help and we all will, so don't hesitate to ask, the forum members are great here, they will answer your questions.

    Never guess or say, "thats good enough or will probably do" on a high HP high RPM engine, it won't be a good result.

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