Locate the CDI unit.
It is usually mounted on the rear fender of the ATV and is covered by a black plastic cover.
Remove the cover from the CDI unit.
Unplug the electrical connectors from the CDI unit. There are usually three connectors: black, yellow, and white.
Connect a multimeter to the CDI unit. The black lead of the multimeter should be connected to the ground terminal of the CDI unit. The red lead of the multimeter should be connected to the trigger terminal of the CDI unit.
Press the multimeter's power button.
The multimeter should read between 30 and 60 volts when the throttle is pulled. If the voltage reading is outside of this range, the CDI unit and the stator will need to be replaced.
Reconnect the electrical connectors to the CDI unit. Replace the cover. Start the ATV. If the ATV starts and runs normally, the CDI unit is functioning properly.
