KL 600 Carb Problem

Discussion in 'Thumpers' started by Triam, Apr 8, 2013.

  1. Triam

    Triam Machinist

    Joined:
    Mar 10, 2013
    Oddometer:
    42
    Location:
    Salt Lake, Utah
    I bought this bike for just $500, and it was running, but I didn't initially notice some of the problems that it had. I've spent some time on it and it's in good working condition except for the fuel mixture. It pops while engine braking, and it looks like they took out the spark arrestor to get more power. I've checked for vacuum leaks, and there aren't any anymore. I ride between 4,000 and 9,500 feet above sea level. The bike will go anywhere now, but without being sure of the mixture that I'm running I hesitate to take it on long rides for fear that it overheats and strands me somewhere. Does someone with more experience with this bike know an easy way to jet it?
    #1
  2. Bogfarth

    Bogfarth Fridge Magnet Safety Tester

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    Dec 26, 2011
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    The Northwet
    Try adjusting your pilot mixture screw first, see if that fixes it. The little bugger sits behind a brass plug you need to remove. Drill a hole into the plug, running a self-tapping screw in, and yarf the plug out with pliers. Do be careful when drilling: you want a hole in the plug, not the mixture screw behind it. 2 1/4 turns out from lightly seated is a good place to start with the mixture screw. At least, from what these guys say...

    http://www.klrforum.com/archive/index.php/t-10716.html
    #2
  3. Beezer

    Beezer Long timer Supporter

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    the plug is prolly aluminum... research the "22 cent" mod for KLRs

    there is also a deceleration valve that might be leaking... look for a plate (I think left side) about the size of a silver dollar... 3 screws. there is a rubber diaphragm under there, check to see if it is torn

    otherwise, popping is mostly an annoyance. the odd bit is that at your altitude I would not expect a lean pop due to the density altitude
    #3
  4. Triam

    Triam Machinist

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    I'm about that far out as it is. Should I go further or should I change my pilot jet? Thanks for the help.
    #4
  5. Triam

    Triam Machinist

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    I thought about doing the .22 cent mod, but I had heard from some that it was good, and from others that the larger hole in the slide will make the slide overly responsive. I'll try shimming the washer next time I have a chance to work on it.
    I'll look for the deceleration valve as well and check the diaphragm.
    As for the altitude, I know that it should be running rich since we have less oxygen than sea level, but my muffler appears to be modified to increase flow, and I think that a lean mixture is a result. I'll take a picture next time I'm at work (I work at a machine shop, so that's where I store it.)
    #5
  6. Triam

    Triam Machinist

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    Salt Lake, Utah
    So I did the 22 cent mod. The slide was already drilled out, but that was the only thing that had been done. I also changed the main jet from a 136 to a 140 and took the idle mixture screw out 3 turns. (I didn't get to the decel pump because I was pressed for time.)
    I took it out for a ride. Upon leaving work, I go on a road that has a speed limit of 55 MPH. Normally I can't get to that speed very quickly, and I have to pin the throttle until I finally make it, hoping that there's enough space between me and the cars that are coming. I pinned it like I normally do and I nearly fell off. The new jet with the needle .038 higher added a ton of power. This bike is so much more fun to ride. Honestly I had regretted buying this bike after the first real ride I took it on, but it's actually fun to ride now.
    When engine braking it pops a bit, but nothing like before. I think I'll still change the idle jet since it pops more in the 25% open throttle than it does with the throttle closed. Maybe I'll take apart the decel pump when I have some time, but the popping is greatly improved.
    Thanks for all the help guys. You've done a ton to improve my riding experience.
    #6
  7. Friedom

    Friedom Onward and upward!

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    Huh. I Should Try This On My 86. I've Had It Up To 75, BUt It'S Running So Rich That My Tail fender Is Quite Black From The Exhaust.

    Have You Done The "Doo"? I've Done It Several TiMes Now On The 600'S. LMK If I Can Help There.
    #7
  8. Triam

    Triam Machinist

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    Mar 10, 2013
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    I took mine up to 81. It handled it like a champ.
    Mine turns the fender black, but I think that it's the valve guide seals. You might want to look at that.
    I haven't even looked at the "doo," but I just sold it to finance a GS850. :wink: I loved the 600, but I almost never took it offroad, and I found myself wanting to go on long rides, but the KL isn't a good bike for that.
    #8
  9. Friedom

    Friedom Onward and upward!

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    I think I'll get a 16 or 17 tooth front sprocket for longer trips and swap it for the 14 off road.

    I'm inclined to think it's not the valve guides or something in the top end, because it only puffs the black under certain throttle conditions.

    "...Whether 'tis nobler in the mind to suffer the slings and arrows of outrageous fortune, or to take arms against a sea of troubles, and by opposing - end them."
    #9
  10. Friedom

    Friedom Onward and upward!

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    Sold mine. Great bike, but not for me anymore. Take care.

    "...Whether 'tis nobler in the mind to suffer the slings and arrows of outrageous fortune, or to take arms against a sea of troubles, and by opposing - end them."
    The spear has been shaken!!
    #10