Motorcycle CDI

Frequently Asked Questions

• How do I choose between AC and DC CDI boxes?

  AC units run without a battery and suit simpler, batteryless bikes but give weaker low‑RPM spark, while DC units need a battery and deliver stronger, more consistent spark and better cold starts; check whether the CDI has a battery feed with the key on to identify the system.
• What should I check for engine size and CDI compatibility?

  Match the CDI’s stated engine size range to your motorcycle’s displacement and confirm the part number and specifications listed by the seller before buying.
• How do engine mods or performance goals affect CDI selection?

  Modified engines generally benefit from programmable or adjustable-timing CDI units to tune timing curves and rev limits for improved throttle response and to avoid detonation.
• What connector, mounting, and installation details matter when choosing a CDI?

  Verify the connector pin arrangement, plug type, and mounting style match your harness and frame layout, and favor units that install without splicing to maintain harness integrity.
• How should I evaluate durability, weather resistance, and maintenance for CDI boxes?

  Choose sealed, heat‑resistant units for demanding conditions, inspect connectors and grounding regularly, avoid low-quality clones that degrade quickly, and replace units showing corrosion or intermittent ignition.