XR600- Donkey Fix Up & Full Rebuild

Discussion in 'Thumpers' started by SlickSix, Jun 1, 2012.

  1. elsalvadorklr

    elsalvadorklr southern xr rider

    Joined:
    Nov 5, 2008
    Oddometer:
    4,158
    Location:
    Columbus, GA
    my bike is fine man! its me thats suffering! jajaj

    after getting a wrong cw rocker I decided to just replace springs and seals and wait till I get my correct reground rocker so I can put in the cw hrc cam! cant wait!

    the mikuni tm38 is a bit lean up top but other than that rocks...

    yeah I figured cm's jajaja we use metric mostly down here too...

    thats still pretty damn big! where do you plan on mounting it?

    I need to install a cooler asap If i want to keep this carb

    Im sure as soon as I install the new cam temps will go up too cause of the spirited riding Ill be doing so Im really interested in what you come up with

    cheers man!

    christian:D
    #41
  2. SlickSix

    SlickSix Been here awhile

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    Hey guys, I´ve been slacking a bit cuz´ my brother still haven´t brought me the frame
    and the rest of the parts but it´s time for some updates.

    I´ve split the cases and it was pretty much as expected, worn out gears, piston in spec but
    a bit scratched, cylinder scratched and out of round. 98mm it is then. :D

    The good news are that the rod is within spec with only minor visual scratching.

    Remember my crusty chamber and valves?

    [​IMG]


    The inner springs were way below specs but not the outside ones. All of them leaked, especially
    the exhaust ones, which were pitted.

    [​IMG]

    [​IMG]
    #42
  3. SlickSix

    SlickSix Been here awhile

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    Cleaned the chamber

    [​IMG]

    Picked up my highly advanced and precise valve turning equipment

    [​IMG]

    Worked the valves with the magic machinery

    [​IMG]

    It´s all good and sealed now

    [​IMG]

    [​IMG]
    #43
  4. Rot Box

    Rot Box Been here awhile

    Joined:
    Oct 31, 2010
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    321
    Location:
    Northernmost Utah
    Great so far :thumb can't wait so see more!
    #44
  5. SlickSix

    SlickSix Been here awhile

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    It´s a shame about the piston, it looks brand new, it´s within spec at 97,48mm, had no
    signs of blowing through but it was probably put on a non fresh cylinder that was
    already out of round. Slapping as left some skirt marks and it was dangerous to leave it as
    is.

    [​IMG]

    The grinder took care of the welded sprocket and shifter. Unfortunately, the previous owner
    welded the shifter directly to the shift shaft and it has to be replaced.

    [​IMG]
    #45
  6. SlickSix

    SlickSix Been here awhile

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    Thanks man :thumb

    Just saw that you have a CR500 :freaky that´s going to be my next project, also
    one of the few bikes that I always wanted after riding one. Or should I say, after
    she took me for a ride :D
    #46
  7. SlickSix

    SlickSix Been here awhile

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    Onto the cases.

    After reading all the trouble that some guys go through to split
    them, I was kind of bummed that it would be a pain to do like some
    that I already had the pleasure to do.

    Not even close. 3 small taps on the crank, 3 on the shaft and 3 more
    on one of the cases "ears" and it was splited.

    Easiest case ever.

    [​IMG]
    #47
  8. SlickSix

    SlickSix Been here awhile

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    Still on the fence about the gears. A couple of gears have some chips and the rest
    are just scored.

    [​IMG]

    [​IMG]

    [​IMG]

    Not sure if you can see it, but the chips are there.
    What say you? Replace now or just wait until they start to jump?
    They didn´t jumped when I picked her up but I wasn´t hard on it. I already have sourced a complete gearbox
    from a NX650 for about 60$. It´s complete and the guy also includes the shift shaft which I have to
    buy anyway. Just waiting for some pictures to check the gears but he said they´re brand new looking.

    I think I´ll just change it and enjoy the wider ratio.
    #48
  9. nikolic

    nikolic Been here awhile

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    Does the shiftshaft and a countershaft from NX fit the XR? I don't see why not, but you're already there before me :D . I plan on spliting it when the season ends!
    #49
  10. SlickSix

    SlickSix Been here awhile

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    Hey nikolic, the shift shaft is the exact same part but not the countershaft. The NX650 one
    is thicker where it fits the right case. Some guys that fit the complete gearbox just machine
    it to fit the XR600 case.

    I already have a new countershaft so I´ll just sell the NX650 which is new by the way.

    Don´t forget to show us your rebuild :D
    #50
  11. nikolic

    nikolic Been here awhile

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    It's kind a hard to find XR parts around here, and as I know it, NX didn't have a countershaft problems! So if it
    gets bad till the winter, I'll probably machine it! Thank's for the info ;)
    #51
  12. mcma111

    mcma111 Long timer

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    The pitted gears won't JUMP as much as throw off little bits of really hard ass steel that love to score the piston/cylinder which leads to oil control problems. They will also start howling when the pitting gets worse. Your best bet is to replace the parts now which will save you all of the labor and gaskets to do this at a later date. Ask me how I know...:huh

    [​IMG]
    #52
  13. nikolic

    nikolic Been here awhile

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    The biggest problem with tiny parts of scrap metal is that they can get stuck to magnet! So you
    can ruin your coils!
    #53
  14. deejay_xr

    deejay_xr Been here awhile

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    Alright, I'm in
    #54
  15. SlickSix

    SlickSix Been here awhile

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    Hey Steve, how´s the leg? Ready to rumble ?
    I forgot to pm you regarding the countershaft...sorry bout that. I found a new one in a dealership
    that went bust and was selling parts at factory cost. I lucked out and they had one. Thanks
    again for the help though. :freaky

    I´ll just replace yes. Better to e safe, right? Already alked to the guy to send me some
    good pictures of the NX650 gearbox.

    By the way, Steve, which spring is recommended to replace on the kickstart assembly?
    The big one that locks it to the case?

    If someone has that little plastic thingy that fits inside the kicksarter spring laying around
    and wants to throw it my way, It´d be great.
    #55
  16. SlickSix

    SlickSix Been here awhile

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    Deejay your bike turned really good, I followed your posts it the supermoto forum too.
    I was thinking of pm´íng you regarding your wheel setup.

    I want to have a spare of street tires on it too.

    By the way, since your from my side of the pond, do you have any good, relatively
    cheap site for parts? I´ve been using ebay with luck, but it´s always good to have
    a direct source...
    #56
  17. mcma111

    mcma111 Long timer

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    The leg is OK, the knees are shot. Perhaps this is why my XR is spotless after the restoration from a couple of years ago...

    The big spring on the kickstarter shaft has never given me any trouble but here is the # 28261-MK2-000

    Plastic collar # 28255-MG3-010
    #57
  18. SlickSix

    SlickSix Been here awhile

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    I know the feeling man, I had my knee cap, femur and right foot busted in a million pieces
    from a car crash a few years ago and the knee is by far the most problematic. I´m young
    and fit and recovered pretty well but it still gives me grief when physically pushed.
    Get well man.

    Regarding the spring, I thought I´ve read somewhere that they tend to break?
    Maybe it was from the shift shaft. I have to go through my rebuild files to check it.
    #58
  19. deejay_xr

    deejay_xr Been here awhile

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    Hey thanks man !

    My current wheel set-up is just 17" Excel rims laced onto stock (powdercoated) hubs.

    I can't really help you with any good sources.
    I buy a lot of things off Ebay as well, for used engine and electrical parts there is this local breaker in Holland that can usually help me out. New engine parts I order from The States. Last time I ordered from www.speedsupplies.com, because they were one of the few that ship outside the US & Canada.

    What source for engine parts do you use?
    #59
  20. mcma111

    mcma111 Long timer

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    Years ago when I first started hanging out around Thumper land on ADV I helped a fella whose XR600 transmission locked up and wouldn't shift. It turned out to be the real fine spring on the shift shaft.

    Gearshaft Return Spring # 24624-MT3-000
    #60