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Help Help wanted please fzr questions

Discussion in 'Yamaha 250cc In-Line 4's' started by Bobbyr, Jan 28, 2021.

  1. Bobbyr

    Bobbyr Member

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    Hello I’m posting for help, I have a couple of questions and I am hoping someone might help me out due to not having a repair manual available.
    fzr 250 3LN1
    What voltage do you get from the 2 pins at the plug for the ignition pick up sensor when cranking?
    The ignition coils- what colour plug runs which coils yellow plug and white plug should run which coil? can someone have a look on a known running bike at these 2 questions?
    Thank you
     
    Bobbyr, Jan 28, 2021
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  2. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

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    Why don't you look in the manuals available on the forum?
     
    Murdo, Jan 28, 2021
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  3. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    GreyImport, Jan 28, 2021
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  4. Bobbyr

    Bobbyr Member

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    Brilliant thank you very much for that, I appreciate it. You dont happen to know the voltage I should be getting on cranking at the ingintion pick up do you?
     
    Bobbyr, Jan 28, 2021
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  5. Bobbyr

    Bobbyr Member

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    I didn't know there was one, In English? I am new to this forum still.
     
    Bobbyr, Jan 28, 2021
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  6. maelstrom

    maelstrom LiteTek Staff Member Premium Member 250cc Vendor Contributing Member

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    At the top of the page, click on the resources link.
     
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  7. DannoXYZ

    DannoXYZ Well-Known Member

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    Answer is mu (none, not related). When trigger bumps move past pick-up sensor, it generates tiny AC with positive and negative wave. You'll see something like this on oscilloscope:

    [​IMG]

    put many of them together and you see something like this:

    [​IMG]

    There is missing tooth that tells ECU where TDC is occurring.

    Test for pick-up coil sensor is to measure its resistance (at room-temperature STP). Then compare to value given in manual.
     
    • Informative Informative x 1
    DannoXYZ, Feb 7, 2021
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  8. DannoXYZ

    DannoXYZ Well-Known Member

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    Also measure peak-to-peak voltage on waveforms and compare to what's listed in manual. In many cases, pick-up coils loosen with vibration and drift away from triggers, lowering signal. Adjust them to 0.25-0.40mm away from trigger teeth. Use some thread-locking compound on fixing bolt.


    Next test is to measure power going to ignition coils. Slide connectors 1/2-way off primary of each coil so you can measure voltage without disconnecting:

    Key ON, start/run swith ON
    1. voltage at coil-1 power = ???
    2. voltage at coil-1 trigger = ???
    3. voltage at coil-2 power = ???
    4. voltage at coil-2 trigger = ???
     
    • Informative Informative x 1
    DannoXYZ, Feb 7, 2021
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  9. DannoXYZ

    DannoXYZ Well-Known Member

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    Next, test for coil-triggering signal from ECU/igniter to coils. These are grounding pulses to dump field at coils. Again, not DC that can be measure with voltmeter. Looks like this on oscilloscope:

    [​IMG]
    Notice grounding pulses are extremely short, ~5ms or less.

    Without oscilloscope, you can use 'noid light to test. These have duration-extending circuitry to lengthen ON time of light long enough so that human eyes can see it. Connect with test-leads to each terminal if coil primary.

    Amazon - noid light
    [​IMG]
     
    • Informative Informative x 1
    DannoXYZ, Feb 7, 2021
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