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Kawasaki FH680D weak spark

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chrtat2000
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2017/05/08 15:48:05 (permalink)
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Kawasaki FH680D weak spark

  I have a Kawasaki FH680D-ES04-R that backfired and now it will not start.  It has a random, weak spark.  Pulled the flywheel and cleaned the charging coil, checked and adjusted the spark plug gap, replaced both coils and the voltage regulator.  The seat switch and brake switch test good.  I have been told that the flywheel (magnets) could be the source of these problems. Has anyone had any experience with this?  It is on a John Deere 737.
Thanks,
CT
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    Mikel1
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    Re: Kawasaki FH680D weak spark 2017/05/10 19:21:38 (permalink)
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    How exactly do you know the spark is weak?
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    chrtat2000
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    Re: Kawasaki FH680D weak spark 2017/05/10 21:11:08 (permalink)
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    Started with a misfire. Tested voltage regulator and coils. Put ignition tester on, spark was weak (not a blue/white spark) and appeared to be intermittent. Safety circuit (seat, brake, etc.) also working properly.
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    Mikel1
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    Re: Kawasaki FH680D weak spark 2017/05/10 22:44:50 (permalink)
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    On the flywheel magnets, magnetism can weaken but it is on the rare side. Is spark still intermittent with the new coils?
    Do you have a link to the tester you used?
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    Rustys
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    Re: Kawasaki FH680D weak spark 2017/05/10 23:56:44 (permalink)
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    Here's a link to the service manual. See section 7. Are you sure the flywheel key isn't sheared off?
    ServiceManual
    post edited by Rustys - 2017/05/12 22:46:31
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    chrtat2000
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    Re: Kawasaki FH680D weak spark 2017/05/12 15:29:44 (permalink)
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      The tester that was used is from Autozone, part number KDT2757.  It is a KD Ignition Tester, calibrated for standard ignitions.
      The magnets on the flywheel show some damage on the leading edges, looks like the coil(s) may have dropped and hit them at some point before i bought the unit.
      The flywheel key is good, had a new one on hand in case the original was damaged when the flywheel was pulled.
    post edited by chrtat2000 - 2017/05/12 15:33:18
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    Rustys
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    Re: Kawasaki FH680D weak spark 2017/05/12 22:56:59 (permalink)
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    Backfiring seems to be a common complaint on that model JD. Check out this link to see what damage was done to this motor. May help you with diagnosing yours.  Backfiring
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    Mikel1
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    Re: Kawasaki FH680D weak spark 2017/05/12 23:30:49 (permalink)
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    chrtat2000
      The tester that was used is from Autozone, part number KDT2757.  It is a KD Ignition Tester, calibrated for standard ignitions.
      The magnets on the flywheel show some damage on the leading edges, looks like the coil(s) may have dropped and hit them at some point before i bought the unit.
      The flywheel key is good, had a new one on hand in case the original was damaged when the flywheel was pulled.


    Have you tried adding a little fuel or a shot of carb cleaner into spark plug holes to see if it tries to start?
    I do have one of those testers, gap is large and normally you get a blue/white from a strong magneto/coil. Heck I can sometimes hear the spark on that tester.
    Quote  #8
    eddyjoe56
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    Re: Kawasaki FH680D weak spark 2017/05/18 16:54:30 (permalink)
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    I have encountered a similar problem on my FH500V.  I have taken the same steps as you and still have not been able to get a spark. I have also unhooked the kill wires to each coil which should eliminate the start switch circuit. I also suspect the magnet on the flywheel but have yet to take that step ($153.00).  I was hoping that someone had encountered this problem and found the solution. I think we are both on the right track and just have to take the last step of a new flywheel with magnet.  Ouch!!!!!
     
    Just to make sure Did You sand the magnets? (Horizontally). Then air gap them to .008"-.012".  Retry starting with everything hooked up. 
    post edited by eddyjoe56 - 2017/05/29 12:34:09
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