AC-CDI v10

New AC-CDI v10 !


  • Programmable AC-CDI
  • For ONE or TWO* cylinders
  • For [2 strokes engines] and for [4 strokes engines with wasted spark*]
    * On 4stk engines with 1 pickup on the crankshaft, one spark occur at compression stroke and one at exhaust stroke. Firing in the exhaust stroke is a wasted spark. Hence the name…
  • Microprocessor control unit
  • Easy programming with USB connection and terminal console
  • Compatible Windows, Linux, Mac
  • One programmable ignition curve
  • Rev from 10 to 20,000 RPM
  • Adjustable timing in 13 steps from 500 to 20,000RPM
  • Soft rev limiter.
  • 1 input for a inductive pickup (VR)
  • Automatic detection for pickup polarity
  • 1 output for a capacitive coil type
  • Non volatile configuration
  • Kill switch
  • Power supply voltage DC 8 to 16 volts
  • Current drain: 100mA
  • Protected against reverse supply voltage
  • Plastic box
  • Wires soldered, no connector provided
  • Made in France

  • Will be available in the SHOP section in the coming January 2020
  • Source and hardware not available


If there is one separate pickup
=> This AC-CDI works.
If there are 2 separate pickups (one for low RPM and one for High RPM)
=> This AC-CDI works.
If there is no separate pickup and the timing is done by using the High Voltage of the stator
=> This AC-CDI will not works
If the engine works with missing teeth
=> This AC-CDI will not works

* Twin-cylinders:
If the engine works with WASTED spark and if there is ONE twin coil.
=> This AC-CDI should works.

If the twin engine doesn’t support wasted spark:
=> This AC-CDI will not work

See: CDI compatibility

Remember that ignition coils are different from TCI to CDI system
– CDI coils have low inductance and impedance around 0.5-0.8ohm
– TCI coils have higher inductance and impedance around 1-3ohm

Remember there are AC-CDI and DC-CDI…


– 1 input for inductive pickup with 1 signal per crank rev.
or for 1 inductive pickup with separate output for low and high rpm (XT600)
– Pickup must give 2 to 30Vac
Points, reluctors, Hall sensor, optical sensors can be used as long as they give only 1 pulse per revolution.
– CDI is not compatible with multi-pulses pickup or missing tooth wheel.

Rev Limiter:

The last RPM value you enter is the “rev limit” that stop all sparks.

Ignition timing

Draw the ignition timing in this XLS sheet.

Terminal console

CoolTerm for Win/Mac/Linux
Teraterm, Putty, Kitty for Win
– Console commands for Mac:
ls /dev/*usbserial*
screen /dev/cn.usbserial-xxxxxxxx 115200 -L
screen /dev/tty.usbserial-xxxxxxxx 115200

– Console commands for Linux:
3 ways to find the COM-port:
tail -f /var/log/syslog | grep USB
dmesg | egrep --color 'serial|ttyS'
ls /dev/ttyUSB*

Config port:
sudo su
stty -a </dev/ttyUSB0
stty -F /dev/ttyUSB0 cs8 115200 time 10

cat /dev/ttyUSB0 & cat > /dev/ttyUSB0

HowTo setup

Setup ACCDIv10r0.pdf



  • Version v10r0c0:
    • First Version.

3 thoughts on “AC-CDI v10”

      1. I’ll be very interested in how it works out on the xt200. I have 2 of them I’m rebuilding and have been looking for a good cdi solution. Thank you so much for all of this.

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