You can bypass a capacitor-discharge ignition (CDI) box temporarily for troubleshooting purposes. Since a CDI box transmits voltage from the pick-up coil in the stator to the ignition coil and does not generate continuous sparks, it cannot store enough voltage to keep the engine running.
- Clear your workspace
Since a CDI box ignites the air and fuel mixture that powers your engine, clear your work area of all flammable liquids, such as gasoline. Keep a fire extinguisher nearby.
- Check the battery
Test the battery to verify it is fully charged. Replace it if necessary.
- Identify the CDI box
Locate a black box with two plugs and a bullet connector. A pin connects to the pick-up coil in the stator, and another pin connects to the ignition coil, which sends the spark to the spark plug.
- Ground the current wire
Ground the wire coming from the stator to the motor.
- Disconnect wires
Disconnect the main wires coming from the CDI box.
- Bypass the CDI box
Attach a jumper wire from the positive battery terminal to the positive wire on the ignition coil. Attach a jumper wire from the negative battery terminal to a ground.
- Observe the engine
If the engine sparks, you have confirmed a failed CPI box. If the engine does not spark, your problem is not a faulty CPI box.