CDI troubleshooting checklist

Most “bad CDI” symptoms come from wiring, grounds, kill switch circuits, or weak stator output.

Run this checklist before swapping parts.

• Kill circuit: unplug/disable the kill switch lead as a test (common cause).
• Grounds: confirm clean engine/frame grounds and tight fasteners.
• Spark plug: known-good plug, correct gap, clean cap/boot.
• Coil: confirm coil connections are tight and not corroded.
• Stator: measure exciter + pickup coils per the service manual specs.
• Harness: wiggle-test while cranking for intermittent opens.