KTM LC4e Ignition

Discussion in 'Thumpers' started by bigtaters, Feb 27, 2006.

  1. bigtaters

    bigtaters Strommer

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    Starting at the beginning... I bought the LC4 about a year ago, and it ran fine. As the weather began to cool off last fall (Atlanta, so not really that cool), the bike began to only run with the choke halfway on, and eventually only at full choke. So, I pulled the carb and gave it a good cleaning (looked like it really didn't need it, though). This improved things a bit, but not totally back to 100%. So, it sat for a couple of weeks and then wouldn't start at all. I yanked the carb again, checked to make sure everthing was clean, drained the gas and replaced with fresh, and gave the air filter a good cleaning and reoiling. Lots of cranking, some backfires, but not running. So, I pulled the spark plug (black) and replaced it. After a few cranks it backfires and starts up. It is putting out some blueish smoke, especially when I roll the throttle on, but seems to be idleing okay. So, I take it out for a nice ride (~150 miles) and the only negative behavior is that it stutters a bit when I hold the throttle at a constant position ( say, less than 1/2 open). I go out a few days later and it won't start. So, I am thinking I have a jetting issue in the carb (bought it with a 157.5 installed and no other mods) causing it to run rich, fouling the plug, making it a pain to start. But, still not sure about the stuttering - guessing it is carb related. Yesterday, I drained the bowl, iinstalled a 150, take the battery off of the charger, hook everything up, and go to start cranking the engine. The starter cycled the engine a couple of times, then something under the side cover started clicking. So, I pull the cover off, and there is some buzzing coming from a either the black box with eight wires coming out of it (CDI, I assume) or the round gold metal piece that has two big wires and two little wires connected to it (an ignition-related switch?).

    So, my questions for the more experienced: should either one of these two pieces be making a buzzing sound? Why is the ?? (switch, I assume) clicking with a fully charged battery? Could this issue be adding to the poor performance of the engine?

    Looking forward to hearing back from you all... please let me know if more info is needed

    Bigtaters
    #1
  2. ChrisC

    ChrisC Amal sex?

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    Hey n00b... edit your post to a type face color we can all read and maybe you'll get an answer.... :cry
    #2
  3. meat popsicle

    meat popsicle Ignostic

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    better? hey ChrisC, wanna repeat yourself on the needle? :lol3

    bigtaters, is the clicking something other than the automatic decompression valve? and you can hear buzzing over the engine?
    #3
  4. bigtaters

    bigtaters Strommer

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    Mea culpa...
    #4
  5. bigtaters

    bigtaters Strommer

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    No, the engine isn't running - this while I am trying to get it to turn over, which it does not. When I depress the ignition button, nothing happens but some clicking from one of the two electrical parts I described. When I investigated where the sound was coming from, I also noticed the buzzing sound, which you have to put your ear down close to these parts to hear. This buzzing occurs any time the key is turned to the on position. The clicking noise is exactly like the sound it makes when the battery dies.

    The battery is a few months old and has been drained and recharged ~5 times since the starting problem began. It reads full charge on the battery charger, and I had no problem starting my buddy's bike up with it as a troubleshooting measure.
    #5
  6. gunnerbuck

    gunnerbuck Island Hopper

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    Just how much oil did you put on the air filter? Too much will foul a plug in short order. Did you try starting the engine with the kickstarter?
    #6
  7. CountPacMan

    CountPacMan Been here awhile

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    These sound EXACTLY like the symptoms I had when my CDI died on my 2000 KTM LC4 Adventure. I replaced mine and its been great since... I now carry a spare.
    #7
  8. markjenn

    markjenn Long timer

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    Dunno about the buzzing (might be normal), but the most likely scenario is a carb problem that caused harder and harder starting, which has eventually fried the starter motor. The starting systems on these bikes are a known problem area.

    I suppose it's possible you've developed an ignition issue in addition, but unlikely. The smoking gun for a carb problem is that it took a bunch of choke to run. So before it wouldn't start, everything started withi a carb problem.

    I think it is unfortunate that so many people with some serious failure in the carb start screwing around with jetting. Like having a 155 vs. a 160 main jet is the reason why I bike won't run except with the choke on.

    You've got a kick-starter - I'd see if you can fire it that way. But you've got something seriously screwed up with the carb.

    - Mark
    #8
  9. meat popsicle

    meat popsicle Ignostic

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    I believe CountPacMan is our resident CDI guru (see the index for his guide); just wanted Bigtaters to know that to put some weight behind his assertion.

    CountPacMan, is there any way to test the CDI? I also ask this because we do need more electrical info on the LC4 in general. :deal
    #9
  10. bigtaters

    bigtaters Strommer

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    Good point on the oil possibly fouling the plug. I have K&Ns on my other vehicles, and I usually tend toward a lighter coat. I can't say exactly how much I put on, but I would say I didn't overdo it. I tried kickstarting until I was red in the face, but no luck.
    #10
  11. bigtaters

    bigtaters Strommer

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    Awesome, this is what I was hoping to hear. Mine is a '99. I read your thread on the KTM lc4 index - which is what got me to me to thinking about the CDI. Now, probably what I don't want to hear... What's the ballpark price on the CDI?

    Thanks again - I'll let you know how it goes.

    Bigtaters
    #11
  12. bigtaters

    bigtaters Strommer

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    Thanks for the reply. The problem with it running with the choke on was mostly solved with a good cleaning, and finished off with a new spark plug. When I can get it started, it runs fine as far as the choke is concerned. So, this is no longer an issue, but I included it since it is where this ongoing problem began showing symptoms, and it might help somebody with more experience diagnose the issue.

    Next, there was a lot of thought and reading before I went in for the jet change. I believe the stock jet is a 147.5. Since the person I bought it from told me he changed out this jet to a 157.5, but didn't finish the rest of the usual mods (drilling out the slide, changing the air jet, opening up the airbox), going back towards the stock jet should be the path to investigate since the bike is running rich. This is, of course, after confirming that everything else was stock, giving a good cleaning, checking the slide operation, diaphragm inegrity, etc, and checking and rechecking that the reassembly was done correctly.

    While in the midst of chasing down the running rich problem, this ignition problem popped up. And it looks like it will probably turn out to be the CDI.

    Thanks for the reply,

    Bigtaters
    #12
  13. meat popsicle

    meat popsicle Ignostic

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    You can look up part prices on the KTM Parts dealers online - CDI (99/00) is about $200 (not including a Munn discount).

    Did you see the "kickstarting the beast" thread in the index? The technique seems to help with the big thumpers. The kicker may still work, or it may not - but exercise is a good thing. :D

    Changing the Air Jet is not a 'usual mod'. It might help you, or it might not. To make sure it's not hurting do everything else first so you know it's effect (rule applies to all mods actually).
    #13
  14. markjenn

    markjenn Long timer

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    I doubt it. But that's easy to check - kick it over with the plug out and see if you get a spark.

    Good luck,

    - Mark
    #14
  15. CountPacMan

    CountPacMan Been here awhile

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    Not necessarily. I got a hell of a spark kicking it over, as a friend of mine will never forget, but it was not sparking regularly. Thats why the bike would run very poorly, especialy at RPMs over 4000 for me. Here is a more complete story:

    I was riding the bike in Japan and was heading to Toyama to take the boat over to Vladivostok in Russia when the bike started becoming choppy on the throttle. I thought I was running out of fuel, but it wasn't it. As I went on it felt more and more like the choke was on. I got to Toyama all right though, loaded it on the boat, and forgot about it for the next few days. When I finally got my bike out of Russian customs, it was VERY hard to get it started and keep alive, but since I only drove it about 3 miles from the port before parking it that evening, I was hoping it would all go away after some partying and vodka. Next afternoon I was going to go for a one hour bike ride to a remote beach with a large group of bikers from Vladivostok, but my bike had the same symptoms. I stopped about 5 miles outside of town to fill up the tank. I couldn't get it restarted. Nothing I did would get it to run. Electric, kick, pushinig, long downhills (I have the clutch lever saftey switch shorted off)... I took the tank off. A Japanese friend had the genius notion of holding the spark plug with his bare hands (and not by the rubber wire either) while I kicked it. Hilarity ensued:lol2

    We definetly had spark. We couldn't figure it out and by now it was night, so I left my bike with a nearby factory gate guard for the night and picked it up the following morning with a truck and took it to a repair shop. Their diagnosis: CDI. It took over 2 weeks for a new one to arrive and Russian customs raped me :deal . When it finally did arrive, we just put the new one in and it fired right up and rode perfect. That was over 30,000 miles ago.

    If you're replacing it anyway, you might as well upgrade to the switchable octane version.
    #15
  16. meat popsicle

    meat popsicle Ignostic

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    The online parts dealer system lists a 99 and an 00 CDI for the 1999 LC4 - is the 00 the switchable version? I would guess the 03 and on would be a bad idea since the high flow head might alter the curve, but I am stepping out on a limb now...
    #16
  17. CountPacMan

    CountPacMan Been here awhile

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    No, I believe the 99 version is what you might call Version 1.0 and should be part number 584.39.031.100

    00 version is 584.39.031.200

    Switchable version is 584.39.031.300

    03 - current version is 584.39.031.500

    what happened to ...400? I have no clue.

    584.39.031.200 and 584.39.031.300 are identical in appearance except for the the .300 has the two extra wires for making the octane switch. The .500 version connects to the new wiring harness.

    584.39.031.300 is not available in the USA. Its not even in dealer's computerized parts database, though it is in the parts manual. You need to order it from a European dealer like Sommer KTM in Germany. I think it was something like $240 with shipping.
    #17
  18. bigtaters

    bigtaters Strommer

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    So, got out the tools and hooked everything back up. The buzzing noise is definitely coming from the CDI. Now, although the battery is fully charged, the electronics are acting like the battery is low. The headlight is dim, the turn signals light up but don't blink, and the bike won't crank at all - not even a clicking noise now. When I kick it, I get a spark at the plug. But, going by the earlier post, this may not mean a whole lot. I'll repost as things progress. Thanks for all the advice and help so far...

    Bigtaters
    #18
  19. markjenn

    markjenn Long timer

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    Sounds like the battery is shot. What makes you think it is "fully charged"? If you've got a voltmeter, what does it show the static battery charge is? I recall that a good battery fresh off a charger will usually be around 13V.

    Motorcycle batteries will not tolerate very many deep discharge cycles before they're toast. Let them sit a week discharged and they're typically shot.

    I honestly don't know what the problem is, but I always go for simple things like batteries and starters before fried CDI boxes. So I'm still betting on the sceanrio that you simply toasted the battery and starter in all the hard starting attempts.

    - Mark
    #19
  20. CountPacMan

    CountPacMan Been here awhile

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    It shouldn't be buzzing. The CDI is all solid state electronics... + the CDI has absolutly nothing to do with your lights/turn signals. Thats most likely your battery. Which might explain your hard starts even with a kick starter. How old is that battery? If more than 2 years, go ahead and replace it before you do anything else.

    Here is a quick tip on starting the bike after its been sitting for a while: set your choke, and then hold in the decomp lever and crank the electric starter for a few seconds and then release the decomp while you keep the starter button pressed. It should fire right up.
    #20