XR600- Donkey Fix Up & Full Rebuild

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

  1. sandwash

    sandwash Long timer

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    Flagstaff Az 7000'
    You will have very good throttle response with the FCR. Many of us DR650 riders have adapted the FCR-MX.Way better throttle response and low end grunt.
  2. SlickSix

    SlickSix Been here awhile

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    Yup, thats a FCRMX too and just gave her the test run and she rocks!!! :ricky

    It was still the 1st break in run but I got say, I can´t see the difference in response between the XR and my CBR F4i!
    That´s good, right? :lol3

    One thing bothers me though. The carb itself rattles and has an hanging idle that could be related to the PJ but I understand that it might be the vaccum plate seal.

    I did clean the carb inside and the seal seemed ok...maybe flattened. Can´t compare it to a new one...
  3. macrae85

    macrae85 Been here awhile

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    399
    Location:
    New Zealand,Scotland,Arizona USA.
    Glad you updated this today,just got THREE XR600s today with 5 engines,though 1 is
    an XL600.Sitting here wondering what direction to take.I reckon get one built mint and
    sell,that should fund the other two! Great thing about Portugal,you dont get the same
    corrosion as us.I once saw an advert for "cyro blasting",sandblasting using ice particles,
    great for cleaning engines,just heat them up after blasting,it's only water,not grit!
    Amazed how light an XR swingarm is.This was only a business proposition,but i'm
    starting to think i might build one to keep one for myself,have to see how my Sth American
    trip fund raising is progressing!
    I'll stick some photos up later........
  4. sandwash

    sandwash Long timer

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    These FCR's carb's do have a "chirp" to them.You did adjust the fuel screw,right-how many turn's from seated? 3 turn's try one size smaller PJ,one turn try 1 one size bigger.Made sure no vacuum leak's first.
  5. SlickSix

    SlickSix Been here awhile

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    I know about the chirp/whistle, they all do it. My cousins WR does it, so I´m not concerned about it.

    It´s the plate rattle that worries me. I did not see any problem with the seal nor excessive wear on the plate but i´ll replace it anyway.

    The fuel screw is 2 1/2 turns out and will check for leaks later on. Will post the ffindings.
  6. SlickSix

    SlickSix Been here awhile

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    3?! Damn, you play it big!

    I would fix 2 of them to sell and the other one keep it :wink:
    Don´t forget to post them :D
  7. SlickSix

    SlickSix Been here awhile

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    Hi guys, just thought I´d give some updates on the big donkey.

    [​IMG]

    [​IMG]

    This thing is a hoot to ride in its element :evil

    There are a few things to tune but for the most part it´s great, it pulls and pulls and pulls :ricky
  8. SlickSix

    SlickSix Been here awhile

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    I´ll make a video as soon as possible, I promise.

    I have a few adjustments to make though.

    Suspension: after rebuilding and assemble, I just left everything at midway and didn´t even set the sag. That was an oversight and it shows big time. The rear doesn´t complain, at least with the medium pace that I´ve run at. The front is not so peaceful.
    At the top of 3rd, headshake sets in. I´m guessing that 15mm down on the front forks is too much and the rear sag really has a happy place.

    Vibration: i know this thumpers do vibrate, but I get a strange one when accelerating from idle up to medium rpms.
    It´s not that hand and feet numbing type, it seems like when the engine is not held tight on its mounts. I have to check them but I´m pretty sure they´re good. It doesn´t make any strange or out of place noises though.

    Do you think that the shaving fof the flywheel has anything to do with it? I just shaved around 400grs.


    Carb:I´ve fitted the 40mm FCRmx with 165/40 and it runs as is but I´m way too rich on the main and lean on the pilot. A NCVT, OBEMN needle, 158,160 MJ, 42,45 PJ and 70,80 LJ are on the way to sort it out. I´ll make the AP mod too and I´ll follow the lead of a guy on Thumpertalk that jetted on a dyno, so my guessing and wasted money will be reduced.

    Apart from that, she rips :D
  9. SlickSix

    SlickSix Been here awhile

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    Left to right: Djubi the old girl, my younger sister, my girl and the 2 latest additions to the family, Bob `the pirate` Marley
    and the Big Donkey

    [​IMG]

    [​IMG]

    [​IMG]
  10. SlickSix

    SlickSix Been here awhile

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    So, riding impressions.

    On the road: I don´t care :lol3 I have other bikes for that.

    Can´t say about singletracking her since there´s not so much of that around here.

    Countryside and 2 Track: Lots of tractable power, easy to ride slow, demanding, but fun, when faster.
    I do not feel she´s heavy like many say, it´s not a lightweight but it´s very manageble and the power she put on the ground helps. I´m 5'10, 85kg, fit athletic build and I´m sure that it helps to manhandle her, but I´m a bit suprised with the easy handling after reading so many guys complaining about the weight.
    Man up, build some muscle and she wont be that bad :deal

    I´m sure that on a singletrack she could be a handfull, but for me and her intended purpose she´s perfect. There are newer, faster, lighter machines and way more expensive machines but none like the mighty XR600! :freaky

    Long live the Thumper!!!
  11. SlickSix

    SlickSix Been here awhile

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    Some mods that I´m really pleased with, shaving the flywheel, 40mm FCRmx with a bigger cam on the accel. tube and the oil radiator.

    She revs up FAST:evil When I sort the jetting, she should be an animal :clap
  12. elsalvadorklr

    elsalvadorklr southern xr rider

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    I think it might...but IU havent done it...mine is smooth at all rpms decel too...

    I know that cw and other engine builders, shave and balance the crank...maybe this would of been nice to do at the same time

    suspension for sure needs to be all the way up on the front especially on the stock forks...springs...
  13. elsalvadorklr

    elsalvadorklr southern xr rider

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    Btw congraaaaaaats!!!!!!!!!!!!!!!!!!!!!:d:d:d:d:d