Tips on throttle cable adjustments on a KTM 990

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by Toddwmac, Apr 8, 2010.

  1. PowerCell

    PowerCell Manufacture

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    :rolleyes
    #21
  2. Blue&Yellow

    Blue&Yellow but orange inside...

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    Right, I've now done it myself. It is not rocket science and there's not need for a big orange specialist. Just adjust like you normally would and leave a little slack, easy. :norton
    #22
  3. sabink

    sabink Been here awhile

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    It's not all about slack.

    I took some time today and looked at the idle motor, throttle valves and cables. I think I understand the need to command the idle motor to release the throttle valves. Please take a look at the pictures and video and comment if I'm on the right path.

    When adjusting the throttle grip free play we can do it using one of the two adjusters in the front or on the rear throttle cable. The problem seems to be that if we adjust the return (front) cable too short we can resist the idle motor and prevent it from opening the throttle enough for correct idle. The front cable must be long enough so that pushing the grip backwards it stops on the resistance point in the grip itself.

    You can see on this video how with wrong adjustment the idle motor transfer movement on the grip.

    http://www.youtube.com/watch?v=ioJTMVQmgoE

    So the idea is to shut off the power when the motor is in it's test cycle and stop it on its disengaged state. Then adjust the throttle so that we cannot pull the bottom (return) cable when twisting back the throttle grip.

    Here is a video how I think we can do that. Sorry for my bad English.

    http://www.youtube.com/watch?v=2G8ejlxCyFU

    PowerCell, what do you think? Will this do the trick?

    I'm attaching a picture with the wrong adjustment that puts force on the idle motor.

    Attached Files:

    #23
  4. sabink

    sabink Been here awhile

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    And this is the adjustment that I cannot put any force on the idle motor. It's a bike specific do not expect to be the same slack on your bike. I also have a G2 cam installed.

    Attached Files:

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  5. mookymoo

    mookymoo Mookish Mook

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    If you watch the video sabink posted above - you will see why its not a simple matter non the 990.

    The EFI is not like a carb.

    Here, I embedded it - but do go read sabink's post

    <iframe title="YouTube video player" width="640" height="390" src="http://www.youtube.com/embed/2G8ejlxCyFU" frameborder="0" allowfullscreen></iframe>
    #25
  6. Torquemada

    Torquemada Adventurer

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    Resurecting an old post. I had someone mess with my return cable tension adjustment so I had to find a way to set it all on the road. Hopefully this is helpful. Experts will chime in if it isn't I'm sure. Hopefully with some technical detail.

    I referenced the video above from sabink and it would seem I got it right. In fact I'd say it's less fussy than before. I focused on paying attention to the unique sound the throttle stepper motor makes at position 0. To get a better feel for that I looked very closely at the throttle grip for when it moved (like 1mm back and forth) and stop it just at that moment.

    WARNING: IF YOU ARE NOT COMFORTABLE WITH DOING THIS, DON'T. TAKE IT TO YOUR DEALER. YOU DON'T WANT TO DAMAGE THE THROTTLE STEPPER MOTOR.

    SETUP
    1. Handlebars straight ahead.
    2. Ignition key OFF
    3. Emergency cutoff switch OFF
    4. Ignition key ON

    LOOSEN CABLES FOR ADJUSTMENT
    5. Loosened both cable adjusters appropriately. Not too much that they would be pushing against each other at the throttle cam.

    POSITION THE SERVO MOTOR WITH EMERGENCY CUTOFF SWITCH
    6. Emergency cutoff switch ON
    7. Listen closely to servo motor sound and switch to OFF. Repeated 4 and 5 until I was sure.

    RETURN CABLE ADJUSTMENT
    8. With right hand roll throttle grip to closed position
    9. With left hand tighten return cable adjuster (front) just until I feel it pull the throttle cam.
    10. With left hand loosen return cable adjuster (front) about 3/4 to 1 turn.
    11. Let go of the grip and tighten the backup nut on the return cable adjuster.

    THROTTLE CABLE ADJUSTMENT
    12. Tighten the throttle cable adjuster (rear) to spec (3 to 5mm) as per the owners manual.

    FINISHING PROCEDURE
    13. Ignition key OFF.
    14. Emergency cutoff switch ON
    15. Start it. Ride it.

    TEST RIDE AND FOLLOW-UP ADJUSTMENT
    It might seem like overkill but I then rode it for the first couple miles smoothly rolling on and off the throttle in the first couple gears to make sure everything was alright and give the bike ECU a chance to learn or complain, stall, cough, backfire, whatever. It rode fine but a few miles later I needed a little more slack taken out of the throttle cable so I repeated steps 1-4,6-7,12-15 again to get it.

    Like I said it responded great after I performed all of the above :nod
    #26
  7. Nailhead

    Nailhead Free at last!

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    I am going to try this ^^

    Mine stalls chronically when the weather is hot & I close the throttle abruptly.

    Thanks. :D
    #27
  8. Zombie025

    Zombie025 Been here awhile

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    Hi,
    i took my 2010 990R apart a while ago, waited for spare parts and now i lost my memory:D
    Can someone please explain (best in pictures) how to reassemble the throttle cable to the throttle body, i'm lost in what was up and which one was down. I know from pulling the grip i shall see it, but want to avoid time consuming mistakes. Thanks for helping a noob:shog
    #28
  9. JTXT

    JTXT Adventurer

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    Tune ECU has a function that was added not too long ago to allow you to force the idle stepper motor to zero so you can properly adjust your throttle cables.
    #29
  10. grant22

    grant22 Been here awhile

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    Just passing on my recent experience adjusting throttle cables. It may or may not be agreeable, but I will state the facts.

    I too recently bought a G2 for my 990 which created additional throttle free play for a total of about 3/8". Way too much and made riding of any type a pain in the arse.

    I called my local ktm dealer and told them I wanted to come in and pay them to connect to the computer and properly adjust the throttle cables. The lead tech got on the phone and said, 'let me save you some time and money.' He explained that as long as I don't adjust against the stepper motors, there's nothing worn with adjusting some free play out of the cables.

    He said to measure my free play, keep the ruler there on the grip, and adjust a little bit at a time until I'm at 1/8", give or take. Just don't go any further.

    I went ahead and tried it and it worked. Bike is much more controllable now and have put 1000 miles on since with no ill effects.

    The tech said he'd love for me to come in and spend money, but said there was just no need for it.
    #30
  11. BikeLugger

    BikeLugger Been here awhile

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    I took out a tiny amount of slack on the OEM KTM grip with this adjuster. I made sure to leave the correct free play.

    What a difference. The power is much more controllable when rolling on and off. Well worth checking if you have a snatchy throttle.
    #31