intermittent spark loss

Discussion in 'Sportster Models' started by goofysniper, Mar 26, 2010.

  1. goofysniper

    goofysniper Member

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    Hi all,
    Hope some of the brilliant minds here can point me in the right direction. I have a 1997 1200s that when riding, on occasion, will just shut down. Will crank but wont fire. After it sits a few minutes will start and run fine and wont happen again for a long time. Rode for bout 10 to 15 minutes then died, after it started, never shut down the rest of the day. Hope someone has heard of this before. thanks in advance.
     
  2. goofysniper

    goofysniper Member

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    i was leaning that way but the dealer told me might be the ignition module. think i'll try the cheaper part first.. thanks
     
  3. glider

    glider Veteran Member

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    Why not try the freon or heat gun to see if you can isolate the bad part before spending any money?

    The cans of computer keyboard cleaner turned upside down will supply the freezing temps to test it out.
     
  4. chester1957

    chester1957 Member

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    Older sporty, odds are it's the ignition module, as said above try heating it with a heat gun and if it dies cool it off with compressed air. Been there done that.
     
  5. goofysniper

    goofysniper Member

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    Thanks for the advice!! Its a weird problem for sure, I can ride 10 minutes and it will kill, then ride for 6 hours with no problem, at least coils are cheap, thinking of just putting a new one on then when i have the money grab a new ign. module. It is an older bike so guess i can expect to replace a part from time to time. Again thanks to all!!
     
  6. Jack Klarich

    Jack Klarich Expert Member

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    Test the coil wit an ohm meter, may save you some time and money. funny thing about electrical parts , if you are wrong no one wants to exchange them. Imagine that,Jack
     
  7. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Earlier the HD the simpler the electrical system (although the schematics were harder to read LOL. Not much consulation IF you have an electrical problem...but as Hobbit says, the highly stressed Ignition coil is subject to damage, but as with any troubleshooting technique, it takes 2 verified symptoms to point to the bad part before considering replacement. Based on age of the bike, and knowing how it was running before should help. Using hairdryer or heatgun with the engine running outside the garage should help, as well as cold spray. Getting access to the electronic ignition module and doing the same will help to isolate problem. Don't forget the crank position sensor and of course all the electrical connections...age, vibration and heat does not fare well to long life, though most of these parts are potted to both resist wear and tear, but make the parts robust and replacement the only option.