2000 fatboy no spark

Discussion in 'Electrical' started by douges42, Aug 8, 2011.

  1. douges42

    douges42 Member

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    I have a 2000 fatboy carburated I was riding the other day and the bike just died it would crank over and headlights worked come to find out i had no spark at the plugs. I can cycle off then back on either the ignition switch or the run off switch on the handle bar and it will start it may go a few feet to a few miles then die again with no spark again cycle off then back on either the ignition switch or switch on the handle bar and it will start. I can cycle either switches while rolling down the road and the bike will start back up. No code was set. The only mods are a s and s super e carb. I replaced the self resetting circuit breaker and the bank angle sensor still have the same problem. I checked wires from the kill switch on the handle bar and the switch itself. Also check the ignition switch. I pulled the gas tank and inspected all wires there. thanks for the help
     
  2. Hoople

    Hoople Account Removed

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    Stock ignition? Do you have a nose cone Hall effect switch for ignition trigger?
     
  3. douges42

    douges42 Member

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    stock ignition and i am not sure what u mean by hall nose cone effect switch but it is all stock

    oh i check the coil primary and secondary sides and the plug wires for correct ohms and everything was within specs there and the plugs are not fouled
     
    Last edited by a moderator: Aug 8, 2011
  4. Hoople

    Hoople Account Removed

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    I can't be of much help because the service manuals I have fall right in between your model year. The 1998 manual I have shows a cam sensor (nose cone) trigger and the 2002 manual I have shows a crank trigger for ignition.

    From what you have said so far, it sounds like a bad trigger sensor. Are you working with a shop manual? If so, is the ignition trigger sensor 3 wire or 2 wire?
     
  5. douges42

    douges42 Member

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    yes i am working with a shop manual there is a 3 wire cam positioner sensor and a 2 wire crank position sensor. both sensors go to the gray connector side of the ignition module the other side of the ignition module is a black connector. i will read up some more to see which sensor tells the coil to supply spark to the plugs
     
  6. douges42

    douges42 Member

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    upon reading more it is a Hall effect device giving accurate timing infromation to the ignition module per the shop manual
     
  7. Hoople

    Hoople Account Removed

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    If your system has both, it means your ignition is single fire. The 3 wire Hall sensor "phases" the ignition to the crankshaft and prevents the spark from firing on TDC of valve overlap (end of exhaust stroke). It's job is to enable the coil to fire ONLY at TDC of the compression stroke and not at TDC of the exhaust stroke. The 2 wire crank sensor, fires the ignition coil at the proper number of degrees of advance.

    If either sensor is not working, no spark will occur. Since the 3 wire hall switch is a logic switch (ON or OFF only) it is easy to check with a voltmeter while you hand turn the engine over. The meter will read either reference voltage or Zero voltage. On or Off like a light switch. Nothing in-between.

    The crank trigger works differently and is harder (not reliable) to check with just a hand meter.
     
  8. douges42

    douges42 Member

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    thanks for the info i will check it out. but why wouldn't it set a code if either the crank or cam sensor was faulty. but like i said it is a problem that comes and goes
     
  9. glider

    glider Veteran Member

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    Not all sensors on the bike will set a code unless they are DOA.
     
  10. douges42

    douges42 Member

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    i was leaning that way to glider