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F8 No spark

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  • F8 No spark

    Hello everyone.
    I currently have abit of a head scratcher.
    I was running my F8 (2 cyl 4 stroke) in some fresh water ready to winterise it when all of a sudden it just cut out. No spluttering or missfire. Just died.
    I currently have no spark and I have checked the following:
    Kill switch circuit continunity. OK
    Pulse coil resistance and AC voltage look ok
    Stator coil resistance and AC voltage look ok.
    CDI output voltage around 200V
    Ignition coil resistance on primary and secondary seem ok.
    I have replaced the ignition coil just incase but i still have no spark.
    The kill switch circuit must be woking as the 200V to the coil goes when i pull the cord.

    Even though the pulse coil resistance reading is ok. . . I am not sure about its ACV output.
    Also not having an oscila scope its difficult to tell if the CDI is giving a pulsed output.
    I have checked and cleaned all ground circuits and now I am at the point where I cant think of anything else to test!

    Any help is greatly recieved.

  • #2
    Just to make sure you know this, the kill switch should not have continuity.
    It should be open, no continuity when in the run position.

    when closed(continuity) it grounds the spark voltage to keep plugs from sparking.

    did you try different plugs?
    did you use a spark tester to see if the plugs were getting spark?
    plug caps.

    Using a DVA adapter with regular volt meter or using a meter designed for measuring the voltages so you can compare them to the specs in service manual helps.
    make sure all inputs and out puts meet specs.

    need good compression, spark(at correct time), and proper fuel to air ratio.

    prove what you can by testing and then figure out the rest by trial and error

    sounds like lost compression, or water in fuel if you have good spark.
    but then carb could have just plugged you or fuel pump went south
    Last edited by 99yam40; 02-11-2019, 12:42 PM.


    • #3
      man if I saw 200V output from the CDIp(first test I would have made, I would not test ANY other ign producing device.
      you do realize when hooked to a spark tester you have to test both coil secondary leads at the same time?