Lc4 640 Extremely stuck choke plunger

Discussion in 'Thumpers' started by gettinold, Sep 1, 2012.

  1. gettinold

    gettinold n00b

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    Hello, anyone have tips on removing a brass choke plunger that's stuck tight in the carb..... Ok I have a 2000 KTM Lc4-e 640 with 9900 hundred miles. Problem is the choke cable broke right where it connects to the brass plunger or what-ever it's called inside the carb. I've soaked it daily with wd-40 with absolutely no effect. Currently the plunger is all beat up from attempts to pull it out and now there is nothing to grab hold of to get it out. My next step was going to be drill and tap the plunger and try screwing a bolt in to have something to pull the plunger out with. But I wanted to see how others have gone about this removal task. Appreciate any tips. Thank you......
    #1
  2. Sacal

    Sacal Been here awhile

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    Can't say i'm familiar with that carb, so don't know if there is a circlip or something holding it in. BUT...if you are certain its metal on metal stuck, I would hit it with a blowtorch and heat that sucker up get it hot through like you are removing a bearing...of course you still need something to get hold of.

    Im sure someone with knowledge of this particular carb who experienced the same issue will be along soon....good luck, hope you get her fixed and back riding soon!
    #2
  3. Groundhog

    Groundhog Been here awhile

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    Compressed air? If you have a circuit diagram you should be able to find a port that leads to the back side of the plunger. Maybe?
    #3
  4. charlie264

    charlie264 Long timer

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    Bottle of malt vinegar.
    #4
  5. r77toy

    r77toy Been here awhile

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    Blowtorch and carburetor, make sure you post video.
    #5
  6. itsatdm

    itsatdm Long timer

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    That plunger is loose fit, I can't imagine it being stuck. I assume you have removed the fitting (plastic?) and spring.
    #6
  7. Aussie Steve

    Aussie Steve Long timer

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    Think its fairly common for these to get stuck in place on bikes that dont use the choke often.

    Would expect carbon and varnish to be holding it in place rather than corrosion, maybe better off trying carby cleaner or acetone to loosen it rather than wd40? (guessing here). Would definitely try to apply it through the choke passages rather than behind the plunger.
    #7
  8. gettinold

    gettinold n00b

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    Yea I removed the plastic and spring, used 10 different solvents and the like and nothing. I ended up using a number 7 drill bit to drill a hole about 3/8" into the plug then used a 1/4"-20 bottom tap and put some threads in the plug. I then screwed in a 3" s.s. hex head 1/4"-20 bolt into the plug, and after an hour of pulling on the bolt then tapping it in, went back and forth till it finally came out. The plug looks like it fused to the inside of the carb.
    #8
  9. bmwktmbill

    bmwktmbill Traveler

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    Next time try your propane torch...with aluminum it is often enough...for red loctite use/overuse and other tight fits it rarely fails me and I have to go for acetylene and oxygen....
    bill
    #9