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  1. #1

    Melted piston disaster

    Hi everyone,

    This post is a continuation of my last, I've reposted since it's a new issue. Please read the latter part of the post below and give me your conclusions:

    http://www.greenhulk.net/forums/show...heared-in-head

    Thanks
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  2. #2
    brisyl's Avatar
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    there is big scratches on the head around where the gasket seated. The valve look good,look more like a piston wash do to water intrusion,if you had a leak and run the ski at high rpm it could cause what you see. Did you used all new gaskets when you rebuilt as suggested?

  3. #3
    no, old gaskets

    i know, should have listened, i live in eastern europe and we wait ages for parts

    thanks for the feedback, the head gasket showed no signs of leakage i could see, maybe water intrusion is impossible to detect

    ---------- Post added at 12:33 AM ---------- Previous post was at 12:23 AM ----------

    by the way those scratches were not made by me, must have been there from the factory, that head did not go out of my site and was never rested on the cylinder face, was always wrapped in something protective. Are you saying a new gasket would have sealed those scratches? is it that critical? even with all that torque on it?

    ---------- Post added at 12:35 AM ---------- Previous post was at 12:33 AM ----------

    i'll put the valve seat photos on here once i have a puller, any ideas how to lap the head? if possible by hand or is that a machine shop job?

  4. #4
    brisyl's Avatar
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    Quote Originally Posted by Ultra260LX View Post
    no, old gaskets

    i know, should have listened, i live in eastern europe and we wait ages for parts

    thanks for the feedback, the head gasket showed no signs of leakage i could see, maybe water intrusion is impossible to detect

    ---------- Post added at 12:33 AM ---------- Previous post was at 12:23 AM ----------

    by the way those scratches were not made by me, must have been there from the factory, that head did not go out of my site and was never rested on the cylinder face, was always wrapped in something protective. Are you saying a new gasket would have sealed those scratches? is it that critical? even with all that torque on it?

    ---------- Post added at 12:35 AM ---------- Previous post was at 12:33 AM ----------

    i'll put the valve seat photos on here once i have a puller, any ideas how to lap the head? if possible by hand or is that a machine shop job?
    From here it's hard to tell if your scratches is to deep, you need to have it check but using the old gaskets and running the ski without doing any leak test, after all the advice that you received, i hate to tell you that you are the main problem. Well let say, you like to learn the costy way and now you need to start from the beginning without cuting corners this time, rebuilding 4 stoke engine is complex and costly so maybe you should consider leaving the rebuild to someone that know's what he's doing before throwing your money in to it

  5. #5

    More photos

    So the big question is, do I have have to disassemble the whole bottom end or can I flush the sump out "in-ski" somehow. Having got myself in the mess I don't want to now give up and palm the whole job off on someone else. Anyway that someone does not exist where I am, at best I find someone who's done some hi-end bike engine rebuilds, I do intend to get their advice anyway. So what's the next step guys?
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  6. #6
    to put a bit more context to my situation shipping this engine to-from someone I can trust 100% will cost me $1000 anyway

    ---------- Post added at 10:45 AM ---------- Previous post was at 08:46 AM ----------

    Can some people reply to my post please? Or am I being shunned for not taking advice )

  7. #7
    nicjak's Avatar
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    shunned we gave you good advise last time but you new better and refused to listen and take advise from mates. good luck. not going there too risky with you im sorry for what has happened.

  8. #8
    brisyl's Avatar
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    Quote Originally Posted by Ultra260LX View Post
    So the big question is, do I have have to disassemble the whole bottom end or can I flush the sump out "in-ski" somehow. Having got myself in the mess I don't want to now give up and palm the whole job off on someone else. Anyway that someone does not exist where I am, at best I find someone who's done some hi-end bike engine rebuilds, I do intend to get their advice anyway. So what's the next step guys?
    Like i said above don't try to cut corners ,you need to start from the beginning, disassemble everything, you need to go down and check everything, metal parts have been thrown everywhere now so you need to inspect every parts from bearings to rod to etc... and no you cannot just flush the sump you need to pull the engine out and do an overall

  9. #9
    ok, noted, thanks i'll do that then, any tips, stuff to watch for on the bottom end?

  10. #10
    brisyl's Avatar
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    Quote Originally Posted by Ultra260LX View Post
    ok, noted, thanks i'll do that then, any tips, stuff to watch for on the bottom end?
    first of all get yourself a shop manual and read it all, you wont rebuild a performance engine by guessing and asking your pal how to, you'll need specs and torque sequence and the right way to do the job,there is only one way to do it right and your pal that rebuild motorcycle won't be able to tell you that info. I hope you know what your doing because this is very costly

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