Honda XL: Troubleshooting Spark Issues

Discussion in 'Old's Cool' started by dorkpunch, Jan 27, 2009.

  1. corsair4360

    corsair4360 Long timer

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    Take it to your favorite local motorcycle mechanic
    #21
  2. bobhead101

    bobhead101 n00b

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    But I feel like it might be a simple fix that i can do and not have to spend any money, I think its something electrical.
    #22
  3. bobhead101

    bobhead101 n00b

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    Iv been riding around on a XL175 but its been missing badly, how can I fix this?
    #23
  4. pommie john

    pommie john Long timer

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    Clean the points and reset the points gap. Check the ignition timing, change the spark plug. That's a good starting point, see if it helps.
    #24
  5. bobhead101

    bobhead101 n00b

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    Thanks pommie john ill try that, I already changed the spark plug tho
    #25
  6. neil w

    neil w Been here awhile

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    Before you do anything else run the bike with the points cover off to see if the points are sparking badly, if ther are and the points are badly burnt/pitted and dirty clean them .

    If they continue to spark it could easily be the condenser
    #26
  7. bobhead101

    bobhead101 n00b

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    I have done that before and the points were sparking, but I didn't think anything of it, they didn't look so dirty ether so I guess its the condenser.
    #27
  8. Andyvh1959

    Andyvh1959 Cheesehead Klompen Supporter

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    An old basic to recall is the color and size of the spark, it should be a fat bright blue/violet spark. Proper timing of the spark is of course critical, but so is spark power and quality. A weak spark is indicated by a tiny blue/violet spark or even a yellowish spark. A yellowish spark indicates low voltage at the plug, it may spark outside the combustion chamber when testing for spark, but that spark is easily overcome under compression. I have even experienced a tiny blue/violet spark when testing an alternate coil, my GN400 started easily but idled slow, and any throttle killed it. I changed out the coil and got a much larger blue/violet spark, the bike started easily and revved quickly, even though I changed nothing else.
    #28
  9. Jerm21

    Jerm21 Been here awhile

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    Reading through this old thread and have found it very helpful. But I'm still a no-go spark-wise.

    Here's the problem I'm experiencing on a bike that I recently acquired ('82 XL100s)

    No spark when purchased. I've hooked a test light to the pigtail off of the 6pin connection coming from the generator. When I kick it, the light is firing as it should. Points look good too. I also bypassed the keyed ignition and tested the handlebar run switch.

    Moving to the coil, it looks to be a coil condenser combo, which I'm not sure if that is stock. The secondary (plug side) is reading the correct ohms per the manual. I'm getting nothing reading-wise on the primary. Am I correct in assuming that the zero reading is because of the condenser or doesn't it matter?

    Also, do I have to "jump" the connection where the battery would be for testing?

    Thanks for any input/insight. I consider myself a decent mechanic, but have been blessed thus far (until now) to not have enountered a trickier electrical problem. Taking over someone else's failed project adds an additional wrinkle, but I figured what better way to learn than jumping into the deep end! :)
    #29
  10. CrazyQuickDraw

    CrazyQuickDraw Adventurer

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    Don't have spark issues but my question seams appropriate for this thread. Redoing the wiring on my '77 125 and while I was able to jimmy up the butchered wire harness to confirm I have spark, I've also been wondering how I should hookup my headlight. I'll be stripping all other unnecessary wiring. Is it possible to run the 6v headlight without a battery?
    #30
  11. dangerDoug

    dangerDoug n00b

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    Great post! thx so much for putting this up DorkPunch
    I had this '78 xl175 since the 90's... love love love but sadly she lost her spark(le) a few years back, died and was left in the proverbial barn out of fear...
    Fear of electrics, electronics, and getting shocked.... Its been a few years of wiring 12v stereos and RV setups- solar, etc and Id pretty much overcome it
    I figure its time to tackle my motoelectrophobia.. (latin name) though im still scared of dentists, and what batter to start on then the ol' XL
    I dug in and, following this tutorial and University of YouTube ( watch out for Prof. IchibanMoto, he'll fiddle your parts after class)
    And have done pretty well so far.. but its hard to be proud when she's still not running. Thats why Im here. HELP
    1st eliminated the simple stuff
    There's juice from the stator, I cleaned the points and they are firing... thumbs up
    but nothing from the coil... boo
    Does anyone know how to tell if its the coil or just the condenser? my bike has the condenser connected to the coil by two soldered wires. Only two wires come from the coil, one wire going to the points, and the heavy one for the plug. I can buy the part for 70$ on eBay but ouch... If its just the condenser I could replace just that for $30
    Pssssst! Anyone know about the resistance?
    No Im not forming a xl- Militia, although we would look good cruzing through protests en masse...
    Im talking ohms... the plug wire gives me nothing, if i pull the cap from the wire I get 5.5 ( on the 20K ohms) so im not sure. the wire to the points gives 1.9-2.1 (on the 200 ohm) Im not sure what any of that means
    thanks for the help cheers
    #31
  12. olefartRich

    olefartRich Senior Discount . . .

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    I know it's an old thread but well written-and I NEED the info! Too bad greedy Photobucket isn't cooperating.....
    #32
  13. aptbldr

    aptbldr easy rider

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    Reportedly a workaround via software run with Chrome browser.
    #33
  14. Sniper X

    Sniper X De Oppresso Liber

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    Ok, I have spark out of test using the light plugged into the blk wht wite the points...it does. I have a new coil new plug a d cap and no spark the new plug.
    #34