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Big thanks to all, my carbs go clunk!

Discussion in 'XJ Technical Chat' started by pederacer, Mar 31, 2010.

  1. pederacer

    pederacer Member

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    I know it has been a while since I have last posted, but I just wanted to thank all of you for all the great information that is available through this community! I haven't posted much because I've been too busy going through the wealth of information, each time finding answers to my questions.

    Back to the important part, my XJ650. It’s been a learning process, and I've probably sunk more into it than I spent on it, but I'm not adding up the receipts!

    I've been chasing a hanging/rising idle for the last year. I thought I had an air leak, maybe running too lean, valve issues. I spent countless hours trying many things, but always thought to myself, "I don't need to clean my slide bores, they look plenty shiny.

    Finally, after a long ride this past weekend, I could not take it any longer. The hanging idle was just wearing me down. I could always fix it by snapping the throttle, but up shifts always sounded like I didn't know how to let off the gas! So, I finally heeded the advice of many here, and polished my slide bores starting with 600 grit sandpaper, working up to 2000 with WD-40 as my lubricant.

    The first ride this afternoon was the best I've had since I've purchased this bike! My idle was smoother, acceleration was much improved, and the engine braking..... What have I been missing! If I slam the throttle shut, it feels like I'm deploying a parachute after making a high speed pass! It’s amazing how much of a difference that one little detail that I had been ignoring, makes!

    So, throughout the past year, my little XJ has received some much needed attention and many parts in an attempt to bring her back to life. I started with all new rubber parts/needles in my carbs, new intake boots, new coils, new brake pads front and rear, a new fuse box, new bearings all around, new cables, the list goes on. However, the best improvement was made with some dedicated polishing time!

    I apologize for the longish post, but was just too happy to not share my great experience stemming from this wonderful community! Of course, I can’t forget to thank our parts guru, the one and only Chacal!

    I've attempted to attach a photo of my ride, I know it still needs more polishing/paint, but for now, she's a runner!


    [​IMG]
     
  2. RickCoMatic

    RickCoMatic Well-Known Member

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    Maybe I should have titled that article, "Your Carbs Need To Go Clunk So You Can Go ZOOM!"

    So, ... Now that you are all pumped-up about the way the Bike is running ... Make a Tool that you can use to Tweak the Mixtures without Pulling the Tank.

    Then, ... Tweak the Mixtures until your Plugs are the Color of a Brown Paper Bag or a Regular Coffee.
    Keep some Brown on them and you're OK.

    The "Leaner" Mixture gives you Big acceleration.

    Just don't get carried away.
    Too lean and you'll kill the engine.
     
  3. WinstonC

    WinstonC Member

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    Looks Nice! I am in the same process, hunting down the same problem,,, hanging idle. Just tore the carbs off and apart tonight. My high idle would come and go (usually at a stop light with everybody watching). I'll be sure to hit the bores a little more, even though they have always clunked fine.
     
  4. RickCoMatic

    RickCoMatic Well-Known Member

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    To put a halt to "Run-a-way Idle"

    You have to have the Throttles practically closed when let-off the gas.

    Make sure the Cable Adjuster isn't tight.
    The Throttle Cable needs to be "Anchored"
    Get the Tank off and throw the Bars over ... end to end.
    Make sure the Cable Sheath does NOT creep. Get the Carb end to where is needs to be to not cause the Linkage to be pulled by a taunt Cable.
    Get the Cable routed right and Duct Tape to the Frame!
     
  5. pederacer

    pederacer Member

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    Rick, don't worry, one of the things I have added to my toolbox is the mixture screw-driver that Chacal carries. Now I just need to do another sync, followed by trying to achieve the perfect color. My past attempts have gotten me close, but not quite.

    On a related note, does anyone know why the plugs would have a slight purple coloration to them?

    Winston, one thing you might want to check is the throttle return springs on the carbs themselves. When I originally tore my rack apart, I failed to note exactly which prongs the springs were supposed to attach to, so I guessed, and guessed wrong on 2 of the carbs! The springs were just a little too weak when not at full extension to pull the butterflies completely shut.

    I can't guarantee this is your problem but worth a shot!
     
  6. RickCoMatic

    RickCoMatic Well-Known Member

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    Once you have it "Just about right" ... the adjustment to get it ... "Right on the money" ... might be quite a small Tweak.

    Real small.
    Like a Noon -to- 12:03PM Tweak.
     

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