AC-CDI v2.4

v2.4

Characteristics.

  • For ONE or TWO* cylinders
  • Highly adaptable.
  • Can handle different pickups coils (Yamaha,Honda,Suzuki,Kawasaki,Zongshen)
  • Use the second pulse of the pickup for LOW RPM , idle and easy start.
  • Use the first pulse of the pickup for HIGH RPM, maximum power.
  • RPM when CDI jump from LOW to HIGH is adjustable.
  • LED indicator.
  • Need a working charging coil for the capacitor. (or a DC converter)
  • Doesn’t need a battery
  • No rev-limiter (Tested at 20,000rpm)
  • Running unit available in the SHOP.

Limitations.

This CDI only does the ignition task, it doesn’t use any safety like neutral and sidestand.

  • Connect directly Neutral switch wire to Neutral indicator.
  • If you need “Side-stand security” then connect Sidestand switch to KILL wire of this CDI
  • Only works with VR pickup (Variable Reluctance AKA pickup coils)
  • Can’t work with Hall sensors or points.

ACCDI v2.2 free no processor for positive first pickups   End Of Live
ACCDI v2.4 not free no processor for positive or negative first pickups Setting via Jumpers
ACCDI v5 free source code available Timing adjustable by customer Setting via PIC programmer EOL
ACCDI v6 free no source code   Hard Settings EOL
ACCDI v7 not free no source code Timing adjustable by customer Setting via PIC programmer
ACCDI v9 not free no source code Timing adjustable by customer Setting via Wifi EOL
ACCDI v10 not free no source code Timing adjustable by customer Setting via USB
DCCDI Atmel free source code available Timing adjustable by customer Setting via ATMEL programmer EOL
DCCDI v2 free no source code Timing adjustable by customer Setting via PIC programmer EOL
DCCDI v7 not free no source code Timing adjustable by customer Setting via PIC programmer  
DCCDI Atiny free source code available Timing adjustable by customer Setting via ATMEL programmer EOL

WIRING

  • How To wire this CDI: Wiring
  • How To hock this CDI on a Yamaha XT600

  •  

    How does it works?

    This AC-CDI use the 100 to 200 Vac provided by the charging coil to charge a capacitor through a rectifier bridge.

    When the pickup is triggered, the CDI turns on a thyristor that discharge the capacitor inside the primary coil.
    This burst of energy into the primary induce a high voltage of few thousand volts into the secondary coil, enough voltage to create a spark at the sparkplug contacts.

    Here is a interesting video description of how a CDI works.


     

    Switches positions

    Sensitivity

    This CDI doesn’t have seamless advance, it jump from LOW advance to HIGH advance.
    The moment when the CDI jump from Low to Full advance is adjustable by potentiometer RV2 (HI).

    Start tuning with RV2 at the maximum value (totally screw) then slowly unscrew it to lower the resistance, therefore the RPM where it switch.


    Compatibility

    Compatible bikes


    Partially compatible bikes


    Not compatible bikes



    TROUBLESHOOTING

    Click here for more info
     

    Step 1

    See: troubleshoot step1
    – Don’t connect the pickup(s)
    – Don’t connect the Kill Switch
    – Connect the ignition coil
    – Remove the sparkplug from the engine and connect it to a GOOD metal frame (ground)
    – Connect the charging coil
    – Connect a DC voltmeter between Ground and Kill output
    DIP Switches positions don’t matter for THIS step.
    Then:
    – Kick start or electric start a few times to load the capacitor.
    The voltmeter should raise up to 100 or 200Vdc.
    If not: Check grounds, connections, joints, charging coil (stator)

    Step 2

    See: troubleshoot step2
    – DIP Switches positions : 1, 3 and 5 are ON. Other switches are OFF
    – Turn RV1 and RV2 to the minimum resistance (position: 0)
    – Kick start or electric start a few times to load the capacitor
    – Connect the +12v plug from a battery to the LO input:
    Led turns on.
    – Capacitor discharge into the ignition coil and one spark must fire at the sparkplug.
    If not: Check grounds, connections, joints, SCR, ignition coil, spark plug cables, spark plug.

    Redo this Step 2 but this time Connect the +12v plug from a battery to the HI input.

    Step 3

    See: troubleshoot step3
    – DIP Switches positions : 1, 3 and 5 are ON. Other switches are OFF
    – Turn RV1 and RV2 to the minimum resistance (position: 0)
    – Kick start or electric start a few times to load the capacitor.
    When the main capacitor is charged and the voltmeter shows 100 to 200Vdc, then:
    – Connect the pickup coil to the LO input.
    – Kick start or electric start once.
    When the piston approaches the TDC and pass in front of the pickup, a positive pulse is send by the pickup and trigger the SCR.
    LED blinks and the capacitor then discharge into the ignition coil and a spark must appear at the sparkplug.
    If not: Check grounds, connections, joints, pickup coil, RV1 and RV2 are at 0, reverse the 2 wires of the pickup coil.


    IGNITIONS FAMILIES


    VIDEOS.

    Click here for more
     

    • Marty bought a 1984 wrecked XT600 without ignition and harness wiring.
      Got it running again even if it seems like he has some carbs works to do…
    • v2.2 fitted a Scooter:
    • Analog CDI on a DR125:
    • Analog CDI on a XT125/1982:
    • Analog CDI on a XT400:
    • Analog CDI on a XT600:
    • Analog CDI at 10,000rpm:

    • Analog CDI at 15,000rpm:

    22 thoughts on “AC-CDI v2.4”

    1. Hi Thierry
      Your circuit is an elegant solution to my problem, I am trying to adapt it the my S3800 Velo Solex, it gives my multiple option to try.
      Cheers Bill

    2. Hi Thierry
      I’m getting all of my components together and I noticed that the parts list and your picture of V2R4C2 don’t match, R1 And R4 hare different values, which is correct?
      Bill

      1. Hi Bill
        Well spotted but it doesn’t matter, it depends on how bright you like the led…
        Beside I’m afraid you’re just wasting your time!
        As described above at “Ignition families“: MAGNETO IS NOT CDI !!

        Th

    3. hi Thierry,,,

      I just ordered for one off my friends this version the analogue AC-DC 2.4 version (via Ebay from you).. looking at the coil, I have a old one from a honda CX500 who had a old CDI type (12v) too… will that work ?
      The motor there is needed for is a xt600 from 1984.. no battery (for now :))

      ps. very interesting site,,, maybe on a later moment we go for the more advanced version but for now this is GREAT !!
      ps2. the original version on the Xt600 is more a AC version than the advanced one ?

      regards
      marty

      1. Thanks Marty,
        “an old CDI type (12v)” is very ambiguous! ACCDI don’t specify “12v” voltage as they are AC!
        Do you mean DC-CDI, TCI, points?
        in one word CDI boxes work with CDI coils type. Those coils have a primary winding from 0.3 to 0.7ohm.

        ps2: Original Yam CDI is more advanced than this analog AC-CDI. Advance timing is more gradual than my ACCDI v2.4
        Th

        1. hey Thierry,,, thanks for the comments… i’m expecting the package soon… and ambitious to start working with it ….. I ‘m experienced with electronics and worked with my bmw r26 on 3 phase generator (6 to 12v) and bought selfmade ignition… I hope that the Xt will start and run smoothly with this 2 step timing

          regards
          marty

    4. Hi Thierry
      This evening i did the first attempt to connect the AC-DCI… I need to check carefully… because i only have wires and everything else as connectior etc are gone πŸ™‚

      my first simpel questions is; for a xt600 (43f) 1984…. 2 pickups ,,, only dipswitch 4 and 5 are on en the rest on off… is that right..

      I have a blinking led. when i kick the starter… but the motor does not run yet. no problem,,, the motor run on an Aliexpress scooter ignition, but the timing was totally wrong and not adjustable.

      but the carb is clean, the mouse is out of the airfilter. and for a simple start is the RV1 and 2 really important ? (for a XT600)? RV2 is on the max as required. RV1 i need to check

      thanks marty

    5. hey Th,
      just to be sure, not complaining πŸ™‚ only asking and not ready yet with building and testing:)
      for the 3 steps I did not had the time, but will do πŸ™‚
      have a nice weekend
      marty

      1. hi thierry,
        i’m happy,,, the xt600 with you AC-CDI works.. i have a few problems on the bike,,, I mean it is not complete… and the carbs are ultra-soon cleaned,,, maybe the adjustment is not yet correct
        but the engine runs,,, i’m really happy that i have a basis to work on

        thanks
        marty

    6. πŸ™‚
      I will buy and DC_CDI too,,,, I want to use that for the primary use, the ignition curve will be more then original. and I like to work on this πŸ™‚

      But for now,,,, I can further work on the Xt,,, Need to check how to adjust the 2 adjustable Resistors. Need to read the “f…king” manual… but that is for later.

      regards
      marty

      1. Hi Th,

        I hope you are well. on this moment i’m replacing the exhaust XT600, so that i’m able to test some more stuff.
        I ordered some connectors, to replace straight connections on the wiring (missing) to the CDI unit in the small box,.

        I will solder the red LED to the outside of the box, what after some last adjustments will be filled with exoxy..

        My question is pro-active on the the RV2, I did not check how to adjust,,, and the the effect on turning the RV2. Due to the fact that i”m not familiar with the running/character of my bike (I bought it from a friend)

        Do you have any guidance on how to adjust the moment for static Low / High “moment” ?

        regards,
        marty

        1. Hi,
          The easier way is to mimic the original behavior of the engine. But as you are not familiar with it you can adjust it this way:
          1) Rev the engine over 5000rpm
          2) Turn RV2 to position 4
          2) Disconnect the pickup LOW wire: Set the switch NΒ°5 to OFF position . Only 4 is ON.
          3) Slowly decrease the RPM to 3000RPM
          4) Turn RV2 counterclockwise until the engine stop.
          5) Reconnect pickup LOW

          Now the CDI will jump frow low to high advance at around 3000rpm

          1. hi TH,
            only a short question on this description on point 3. is 3000 RPM the best RPM to switch to max timing advantage. I don’t have the experience yet in practice, but can imagine that with 2000, or 2500 RPM that already would work fine too ?
            yes official it is much higher in a nice curve… and this is a hard switch, what is fine… but when is the best moment…
            regards
            marty

            1. Hi marty,

              Yes it will works at 2000 – 2500rpm and you can have the feeling of more power but is bad for the piston.
              Too much advance will make the engine knock !
              It’s safer to follow the Yam original timing.
              Th

    7. hey thierry,

      yes , you are right… I don’t want to hear it … but yes… understand.
      on the moment I have a battery , and starting on the wiring of the bike.
      i’m in the market for the more advanced one,,, V10..
      we keep in touch,,,
      regards
      marty

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