Starting problems with 07 KTM 640

Discussion in 'Thumpers' started by Robbiedebob, Dec 8, 2009.

  1. Robbiedebob

    Robbiedebob Been here awhile

    Joined:
    Apr 23, 2009
    Oddometer:
    130
    Location:
    The Leap (via Mackay) , Queensland
    Guys

    Need some help it's driving me crazy. It first started a couple of months ago when it wouldn't start in neutral. I clicked it into gear then back into neutral and it started no problems. A week or so later it did it again but this time when I did the above proceedure it still didn't start so I left it in gear pulled the clutch and it fired up.
    This continued to become more frequent as the days went on. I use my bike for the daily commute aswell as seeing the country. It got so bad that the neutral light would flicker and then dissapear, the dash lights would'nt come on and anything I tried would not start it. It eventually come to the point of having to turn the ignition key on hit the button, hope it would start (because it didn't happen every time) if not put it in gear rock it back and forward until it made a small click sound and the dash lights came on and then she'd fire up.
    Took it to the bike shop who replaced the neutral switch and all has been good for a few days until yesterday. Same thing happening.It's obviously an electrical gremlin but any thoughts as to where to start looking.
    I just went to start it this morning. Ignition on, all lights and display working except for the neutral light. Press starter button, nothing. Pull in clutch (in neutral) fired up straight away.

    Cheers
    #1
  2. Luke

    Luke GPoET&P

    Joined:
    Aug 25, 2004
    Oddometer:
    4,472
    Location:
    Beaverton, OR
    The fact that rocking it makes it work sounds really weird.


    The bike is designed to not start unless the neutral or clutch switch are closed.

    Find the neutral switch (it's near the countershaft). Clean off the contact- it's exposed, and follow the wire up under the tank to see if it's broken anywhere.

    The neutral switch grounds it's contact when in neutral, and opens it when in gear.

    Also check and clean up the ground lugs. There are several- a couple near the battery and ignition module, and one up in the wiring mess under the dash. Check the battery terminals.

    Those are just standard guesses. What sort of click is it? Tiny relay click or transmission shifting click?
    #2
  3. Zerodog

    Zerodog Long timer

    Joined:
    Jun 9, 2006
    Oddometer:
    1,233
    Location:
    SLC, UT
    My money is on the ignition switch. How many miles do you have?

    All those vibes on little solder joints. Mine crapped out at about 20,000 miles. My buddies did at 22,000. I fixed my old one and filled it full of silicone. Then I bought a new one and pulled it apart and filled it full of silicone too. That is one way to get your ass stranded in the middle of fucking no where.
    #3
  4. gunnerbuck

    gunnerbuck Island Hopper

    Joined:
    Nov 19, 2005
    Oddometer:
    5,077
    Location:
    N.V.I, B.C.
    Zerodog is likely on the right track... Take a hold of the wire loom going into the bottom of the switch, give it a wiggle and see if the lights flicker....

    There is a relay under the right side cover back of the Ignition CDI module that is often suspect... Check the wires going into this for breaks and bare spots.... Another area that wires tend to rub is under the dash panel... Remove it and unplug the speedo/tach and powerlet and then go over the wires that are ziptied to the crossframe as well as the plug clusters.... These checks should be part of your regular maintenance as the vibration combined with the thin shielding on the wires can lead to problems....
    #4
  5. bmwktmbill

    bmwktmbill Traveler

    Joined:
    Jul 16, 2005
    Oddometer:
    5,594
    Location:
    Traveler
    This summer I kept getting a dead battery if the bike sat for 24 hours. Without even trying hard I found 3 bare spot wires under the dash and one under the right side cover.

    Things are back to normal now.
    bill
    #5
  6. Hipster

    Hipster Long timer

    Joined:
    Aug 31, 2004
    Oddometer:
    2,030
    Location:
    Mpls, Mn.
    +1 on the ignition switch. My '01 640 was acting up on me and disassembling the switch for cleaning helped for a while but, I wound up replacing the switch to eliminate the problems.

    #6
  7. dog'meat

    dog'meat Presidient

    Joined:
    Sep 4, 2008
    Oddometer:
    168
    Location:
    Cromagna
    Mine started to do the same kind of crap...

    I found that the wire crimped to the connector at the positive of the battery -which is hidden under a rubber boot- was completely cut, (those vibes are serious thing) only grabbed by the boot but making random contact as the bike moves...

    I found that when at the blackout moment it went back on upon a hit made with my fist at the back of the seat, just over the battery place...
    #7
  8. Robbiedebob

    Robbiedebob Been here awhile

    Joined:
    Apr 23, 2009
    Oddometer:
    130
    Location:
    The Leap (via Mackay) , Queensland
    Thanks for all the suggestions. Sorry I have not replied earlier but I have had computer problems. Damm windows 7.
    I have gone into the dash and checked all the wires and have not found any bare wires. The neutral light hardly comes on anymore but the bike starts straight away when I pull the clutch in. I did find a lose earth connection under the seat. Next step is to get the ignition checked. I will keep you posted.

    Cheers
    #8
  9. Fogger

    Fogger Wanderer

    Joined:
    Dec 25, 2007
    Oddometer:
    1
    Location:
    Sydney, Australia
    I've had the cables rub through the insulation, and had the battery wire break on my '05 640sm. The cable rub occurred in the main wiring loom near the ignition box. Whoever had installed it at the factory had put a twist in the loom that forced the wires against each other. It's been problem free since I fixed it and untwisted the loom. A mates '02 640 Enduro had a similar problem that caused it to cut out randomly. I think his problems were caused by wiring near the ignition switch. My local KTM dealer gave me the impression that it was a fairly common issue.
    #9