Many modern motorcycles and scooters have a particular type of ignition system known as “CDI ignition.”
In this blog post, you’ll discover more about this ignition system, including:
- What it stands for
- How it works
- The 5 components of a typical CDI system
Prefer to get this information in podcast form? Listen to the 30 Minute Motorcycling Podcast episode about CDI Ignition:
What is CDI Ignition?
Benefits of CDI ignition
The most significant advantage of CDI ignition is that you can easily get a reliable ignition spark. Compared to an inductive system (i.e., a system that relies on the ignition coil to do most of the work), the charging time for a CDI system is shorter. And because there are few mechanical parts, a CDI ignition system is low-maintenance and requires little extra adjustments.Instead, power is delivered through a metal cable that tensions as you squeeze the brake lever - similar to how many motorcycle clutches work.
Although not so much on modern motorcycles, these brakes are highly common on bicycles and e-bikes.
How Does CDI Ignition Work?
So where does the capacitor get its power from?
5 Common Parts of a CDI Ignition System
1. Alternator or flywheel magneto
2. CDI Box
- Thrysistor
- An inverter
3. Trigger mechanism
4. High Tension coil
5. The spark plug
True – the spark plug isn’t unique to the CDI system, but it is the final destination for the electric spark.
Once the spark reaches the spark plug (specifically the spark plug’s electrodes), it:
1: “Jumps” across a tiny gap between the spark plug’s center and ground electrodes,
2: Ignites the compressed fuel mixture during the ignition