LC4 CDI issues?

Discussion in 'Thumpers' started by djchan, Nov 6, 2006.

  1. djchan

    djchan Long timer

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    So I'm leaving the house on Sunday - headed for a powerline trail I've only spent a few minutes on.... and she dies - dead - just 1/8th mile from the house. I've recently had some mild glitches. Riding down the road and the bike stops and then restarts almost immediately on it's own.

    The battery is turning the engine over - and I'm smelling gas. So I push it (uphill) home and stick it in the garage. Last night I tried to search for some threads on LC4 CDI failure. I'm sure they are there but I was unable to find the right combo of words to pull it off.

    Can anyone give me a hint as to where to find this info? Seems I've seen at least 1 thread along these same lines.

    TIA

    Dean
    #1
  2. creeper

    creeper Still alive...

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    Check the "usual suspects" first Dean. The spark plug cap is a screw-on affair, and the high tension lead can corrode... resulting in a partial or complete loss of spark.
    The fix is to remove and clean the cap, snip 3/8" off the high tension lead and reinstall the cap...good and tight, with maybe a little di-electric grease for good measure.

    A few other simple things to check before you start throwing money at it are going to be connections, grounds and the start/run switch, which can allow the starter system to work, but not the ignition.
    If you have a multitester it's much easier to check for low resistance continuity than to make assumptions based on eyeballing things... unless of course you find something obvious.

    My ignition and starter breakout schematics should make things a little easier.
    These are for a '03 and later 640A, so a few things are different... like the location of fuses for starters.

    [​IMG]

    [​IMG]

    C
    #2
  3. Speaker

    Speaker Been here awhile

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    I'm in the same boat right now. No spark. Tried creepers suggestion, no spark. Replaced plug, no spark. New coil, no spark. Stator's on order :bluduh
    #3
  4. crazybrit

    crazybrit Long timer

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    Did you perform any kind of resistance check on the stator coil. Normally this will show partially/totally shorted when you have weak/no spark, assuming it's the stator.
    #4
  5. Speaker

    Speaker Been here awhile

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    yeah, don't have a multimeter so to a shop to confirm. Infinite resistance across black red, green red. here's the "specs" it should be at

    <table border="1"> <tbody><tr><td>OHMs</td> <td bgcolor="#ff6600">Red</td> <td bgcolor="#66ff00">green</td> <td bgcolor="#c0c0c0">black</td> <td bgcolor="#ffff99">yellow</td> <td bgcolor="#66ffff">blue</td> </tr> <tr> <td bgcolor="#ff6600">red</td> <td>
    </td> <td>1777</td> <td>1754</td> <td> </td> <td> </td> </tr> <tr> <td bgcolor="#66ff00">green</td> <td>1777</td> <td>
    </td> <td>23</td> <td> </td> <td> </td> </tr> <tr> <td bgcolor="#c0c0c0">black</td> <td>1754</td> <td>23</td> <td>
    </td> <td> </td> <td> </td> </tr> <tr> <td bgcolor="#ffff99">yellow</td> <td> </td> <td> </td> <td> </td> <td>
    </td> <td>0,2</td> </tr> <tr> <td bgcolor="#66ffff">blue</td> <td> </td> <td> </td> <td> </td> <td>0,2</td> </tr></tbody> </table>
    #5
  6. ktmnate

    ktmnate Long timer

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    I had a similar problem. It was on a '97 620 RXC/e. It turned out to be a pulse generator. Which was torn apart by a circlip that held on a freewheel gear.



    Nate
    #6
  7. CountPacMan

    CountPacMan Been here awhile

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    I had the same thing happen to me on my 2000 LC4 Adventure a couple of years ago. It WAS the CDI. good luck...
    #7
  8. Castleman

    Castleman Guest

    My flame out ended up being the pulser coil
    #8
  9. bigtaters

    bigtaters Strommer

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    My 99 LC4E died a while back. I suspected the CDI unit since it was making a buzzing noise when the key was turned to the 'run' position, and some members here and KTM said that it should not buzz. I went through the cheap stuff first, and eventually ran through the electrical system check a few times. Everything met spec, so I bought a new CDI unit. Installed it, put in some fresh gas, cleaned the spark plug and it fired up. From what I gather from KTM, unless your local shop has a test bench (mine laughed when I asked), the only way to check the CDI is replacing it (or finding a buddy with a compatible model/year who'll let you borrow it). Per KTM, the CDI is a non-refundable item, and a bit pricey, so make sure you rule out the cheap/free/troubleshootable stuff first. Good luck!
    #9
  10. djchan

    djchan Long timer

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    Thanks guys - I've got a few directions to head prior to opening the wallet - just what I was looking for.

    Dean
    #10
  11. GS Spirit

    GS Spirit Downsizing

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    #11
  12. meat popsicle

    meat popsicle Ignostic

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    excellent! cross-linking threads :beer
    #12
  13. djchan

    djchan Long timer

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    Fixed in 30 seconds! I took a look at the coil before even taking the tank off. It was swinging quite easily. Turns out the puck and screw for the tank were loose - and thats also the holddown bolt for the coil. The coil was shorting out and nothing got to the plug. Thank heavens it was easy cause I'm a complete nincompoop when it comes to electrical diagnostics.

    Thanks for all the good tips.

    Dean
    #13
  14. overlandr

    overlandr Dystopist

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    Mmmm - CLTs :tb
    #14