Diagnosing Intermittent Soul-Draining Problems?

Discussion in 'Airheads' started by wiznas, Sep 20, 2013.

  1. Warin

    Warin Retired

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    Yep. But on a trip my brain tends to go on holiday too. Can take a while for it to come back :D
    #21
  2. Plaka

    Plaka Brevis illi vita est

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    I asked a buddy once, who had done many very long trips (years) if he ever listens to music on helmet speakers. He said, "no, I just like to listen to the engine". I tried helmet speakers myself once. I found I preferred listening to the engine too. I'm more in tune with the bike on a trip. In daily riding if the carbs or valves get out I won't notice. On a trip I notice immediately.
    #22
  3. wiznas

    wiznas Adventurer

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    Oh yeah. I'm all for listening to the sweet buzz of the engine. I would feel like I was being rude any other way, like listening to an ipod while a friend is talking. I'm really trying to make this relationship work.

    Okay update. I was happy to find the problem persisted, when checking the plugs, I turn the switch to run, but before I hit start both plugs are sparking almost nonstop for about 30 seconds. Good blue spark. Then they go dark and cranking creates no spark.

    Took the ignition coil off, cleaned it, didn't need much, no corrosion where the spark plug wires go in. (wire ends look good too, shiny brass)

    This is probably another noob question, but the resistance I am measuring is between the two wire contacts, NOT the spark plug wire receptacles, correct?

    I measured 2 ohms between the only two contacts (besides where the plugs go). So does that mean it's a bad coil? Or is that close enough to 1.5 to be "okay"?

    Scientifically I don't get the pre-ignition spark, if corrosion has caused a higher resistance, I understand how that could prevent a spark, but that pre-sparking craziness seems like a shorted connection somewhere, what do you guys think? Have you ever seen that before?

    Thanks for sharing so much wisdom!
    daniel
    #23
  4. Warin

    Warin Retired

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    1) Have you removed the faulty tachometer from the circuit? If not do it now.

    2) the coil, spark plugs, spark plug wires are NOT causing this problem. Nor is any fuel issue.

    ================================
    There should be NO sparks when the motor is not turning over. This could be the tachometer .. disconnect it and you have removed it from the possible problem makers.

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    Using a resistance meter at low setting means you must take into account the resistance of your test leads ... connect the leads together and ideally the reading should be 0, but might just read 0.5 ohms. If you have this 'zero offset' you should then take it away from your other reading eg 2 -0.5 = 1.5.... I'd say your reading of 2 is close enough to 1.5 not to worry. You can get a lot of variation with contact resistance .. especially if you are not practiced in taking these types or readings. For basic fault finding you look for conduction - low ohms indication and insulation - high ohms indication.

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    I'd not suspect the coil of causing the kind of things you have happening. We are all assuming you have the standard ignition system.

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    If you still have the same kind of problems after the tacho disconnect then I'd check for a crushed group of wires under the front engine cover that go from the bean can to the control unit ...
    #24
  5. wiznas

    wiznas Adventurer

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    Warin,

    Good call on the multimeter etiquette, measured .4 across the test leads. So I guess it's not the coil. All this testing was indeed done without the tachometer connected. I'll be scouring for screwy wires today!

    Thankyou
    dm
    #25
  6. Plaka

    Plaka Brevis illi vita est

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    Yeah, that presparking sounds very weird. My first guess would be hall sender, my second would be ignition module.

    A short can indeed cause a spark at the plugs, but this would have to be repeated intermittent shorts in fast succession. One way to separate hall vs module issues is to short the center lead of the hall plug, engine side, ignition on. This should produce a spark.

    if it keeps up, I would unplug the hall/bean can. Don't lose the wire clip.

    If it still happens, unplug the ignition module at the module. Don't lose the wire clip.




    Then see what happens. if it goes away, do further diagnostics on both components. Snowbums page on this covers the drill. Meat is about halfway down, skip the history lessons for the moment.

    I keep a spare module or two around. not a big expense and running a plug lead open will fry a module immediately. I'v done it. So having a spare on hand makes sense to me. I'll need it someday and I have one for diagnostics. Spare bean cans can be a larger expense.
    #26
  7. SpaceManSpiff

    SpaceManSpiff Man of Mystery

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    Wiznas,
    I know NOTHING about airheads, but I did have soul-draining Kawasaki KZ650 once. Sweetheart when she ran, but intermittently (seemingly at random like your bike) would just die. Sometimes, it would re-start other times not. Had to be loaded up onto a flatbed truck more than once and towed home. The time it died and coasted to a stop just outside the county dump was almost more than I could take. :hair I almost left it there, but had changed my mind, by the time I had trudged the 5 miles home (in full leathers).

    You might find it something simple a problem in the wiring (not necessarily in the ignition components) elsewhere on the bike.

    On my soul-sucker I eventually traced it back to a short in the wiring harness in the rear. Damn mice ate the insulation on some wires going to the tail/brake light blinkers and occassionally (a bump, humidity, phase of the moon, idk) would cause a short screwing everything up...and poof! no sparky.

    HTH,
    spaceman
    #27
  8. apt13

    apt13 Been here awhile

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    had a kinda similar problem a couple years ago. bike would die and refuse to start back up unless i waited a couple hours. or once warmed up i would stop for gas, and the bike wouldn't start back up. after much going over, turned out it was the battery cables. the positive cable looked fine on the outside, but once i cut it open it was completely burnt through the middle. once i replaced everything with new pos and neg battery cables, everything has been fine since. i will say that i never experienced any hiccups or backfiring. and the bike never died while riding. it just didn't want to restart seemingly until it "cooled down." might be worth peeking at if none of the other options work.
    #28
  9. wiznas

    wiznas Adventurer

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    Yahoo! you guys were right, tested a bad ignition control module. Replaced it yesterday and got regular sparks again. Thanks so much for all the troubleshooting advice! I came out of the process with a couple more questions but I'll post them as new topics to keep the info organized. Thanks again.
    daniel
    #29
  10. _cy_

    _cy_ Long timer

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    glad you finally nailed it! now you know why my preference is beancan with points...
    #30