Design to simulate pickup at different RPM to test TCI, CDI, Tachometers, Power valves and ignition coils.
And to extract the advance curve from a Digital TCI or CDI.




The simulated pickup signal is 30Vpp (+15v and -15v) or can be reduced to 20Vpp (+10v -10v) with jumper N°2


The most advanced feature!

  • With the help of a Capacitive Probe hooked to the sparkplug wire, this tester can measure the time that goes by between transmitted pickup and received spark and display the advance timing of the TCI/CDI under test.
    To do so you need a external High Voltage power supply (not provided)

  • Detect RPM limiter
  • Can test Digital CDI/TCI (with processor inside)
    Cannot test simple analog CDI like GY6 (that only use resistors and capacitors) as the advance timing comes mainly from the voltage of the VR, not from inside those CDI.


Tester comes along with a simple but useful one way scope!

  • Display the pickup signal generated.
  • Display the sparkplug signal captured by the capacitive probe.
  • Can be used as a simple scope (BW:1KHz.)
  • AC Input from 2Vac until 100Vac. AC only (no DC)
  • Scope display time per division
  • Automatic Frequency measurement
  • RPM display.
  • Display can be freeze with HOLD button in order to analyze, take photo, etc….
  • A simple timebase is available to adjust Horizontal position from 0.8ms to 80ms/div
    (Zoom IN & OUT buttons)

  • Automatic Trigger to stabilize trace.
  • Persistence function to show random events or voltage/frequency changes
  • Values display can be turned off
  • Test pin puts out a 100Hz test square signal to test probe and scope.

  • View the scope on a PC.
    With the help of “Serial oscilloscope” software, connect the scope to a PC and enjoy a big display and more functionalities:
    (USB at 115200Kb, BandWidth:200Hz)

    Warning when applying high voltage:
    The PCB ground will be connected to the voltage!
    The board MUST be isolated (Use a plastic box)
    DON’T touch the input selectors when applying voltage!
    ALWAYS disconnect input BEFORE changing sensitivity jumpers.


TCI-CDI Tester v4r3c0 Parts list components.pdf



  • How a pickup works?
  • Testing a Analog CDI (Not able to extract the advance timing as no proc inside.):

    Scope the Analog CDI v2.4:

    Why the tester shows: advance = -350°?
    Minus sign mean that spark appear ATDC (after TDC) So it’s no more advance but it’s retard.

    Extracting advance curve from a Digital CDI:


3 thoughts on “CDI TESTER v4 and SCOPE”

  1. You really did a great job Sir Thierry. I been a fan of yours since the day your website was up, and every time someone ask me about cdi, only your link and website is what I recommend for them to have a slight knowledge about CDI.

    I didn’t attempt to enhance my knowledge with it, since I no longer interested in motorcycling due to poor standard here in my country, laws, safety, discipline of riders. and others.

    I just want to congratulate your undying passion about cdi and hopefully soon you’ll have your own brand of CDI. Thank you.

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