The Complete Guide to 6 Pin CDI Wiring Diagrams

If you own a motorbike, ATV, or other small engine vehicle with a CDI (Capacitor Discharge Ignition) system, you’ve likely needed to diagnose an ignition problem at some point. And to do that, you need to understand how to read and troubleshoot a 6 pin CDI wiring diagram.

This comprehensive guide will teach you everything you need to know about 6 pin CDI systems—from what each wire does, how to read the wiring diagram, common problems and troubleshooting tips, to how CDI ignition works. Whether you’re an experienced mechanic or a DIYer new to small engine repair, this guide will help you master 6 pin CDI wiring diagrams.

What is a 6 Pin CDI System?

CDI or “Capacitor Discharge Ignition” refers to a type of electronic ignition system commonly found on motorbikes, ATVs, jet skis, snowmobiles, chainsaws, and other small engines.

The CDI system uses electronic components to generate a higher voltage spark compared to traditional ignition systems. This hotter spark allows for better combustion, resulting in more horsepower and acceleration.

The CDI unit or “black box” has 6 wires coming out of it, hence the name 6 pin CDI. These wires connect to various engine components to operate the ignition system. The wires are for:

• Power – Typically a red wire that connects to the positive +12V from the battery to power the CDI unit.
• Trigger – Usually a green or white wire that connects to the pickup coil. The pickup sends a pulsing signal to the CDI to tell it when to fire the spark plug.
• Ground – A black wire that grounds the CDI case and completes the circuit.
• Coil – Two wires that connect to the primary windings on the ignition coil. The CDI sends voltage pulses through these wires to the coil which steps up the voltage to generate the spark.

Inside the CDI box contains electronic circuitry like transistors and capacitors to amplify the trigger signal from the pickup coil, store energy, and release it to the ignition coil.

The CDI allows for more precise spark timing and stronger spark over traditional points ignition systems. But the added electronics also mean more potential failure points.

How to Read a 6 Pin CDI Wiring Diagram?

If you want to diagnose and fix ignition problems on your CDI-equipped vehicle, you need to know how to read and understand the 6 pin CDI wiring diagram.

Let’s walk through what each wire does in a typical 6 pin CDI wiring schematic:

1. Power

The power wire is typically a red wire coming from the CDI box that connects to the positive +12V from the battery. This provides power to run the internal electronics of the CDI unit.

Make sure this wire has 12+ volts with the key on. No voltage here means the CDI will not operate.

2. Trigger

The trigger wire is usually a green or white wire that connects from the CDI to the pickup coil mounted near the flywheel.

As the flywheel spins with magnets passing by, the pickup coil generates a pulsing AC signal that it sends to the CDI box. This acts as the trigger to tell the CDI when to fire the spark plug.

You should see 0.4-2.0V AC on this wire with the engine spinning. No signal indicates a bad pickup coil or loose wiring.

3. Ground

The ground wire, usually black, connects the metal case of the CDI unit to a chassis ground or sometimes directly to the negative – battery terminal.

This completed the circuit and ensures proper CDI operation. Make sure it has continuity to clean ground.

4. Coil Wires

There will be two wires, often yellow or orange, that connect from the CDI to the ignition coil primary windings.

When the CDI receives the trigger signal, it sends a 12V pulse to the coil through these wires. The coil uses a step-up transformer effect to convert this to 25,000+ volts to jump the spark plug gap.

You should see 12V on these wires when triggering the ignition system. No voltage points to a bad CDI box.

5. The CDI Box

At the heart of the system is the CDI box itself. It contains electronic circuitry like transistors, diodes and capacitors to amplify the trigger signal, store energy briefly, and release it to the ignition coil.

Capacitors charge up to around 400V then discharge current into the coil primary when triggered, creating a very abrupt, high current pulse. This is key to generating the strong spark.

Common CDI Problems and Troubleshooting

Since CDI systems contain more electronics than traditional ignition systems, there are a few more potential failure points to diagnose. Here are some of the most common 6 pin CDI problems and how to troubleshoot them:

No Spark

If your engine suddenly loses spark, the first thing to check is:

• Trigger Signal – Use a multimeter to check the trigger wire from the pickup coil while cranking the engine. You should see 0.4-2V AC volts if the pickup is working properly. No volts means it’s faulty.
• Power – Verify 12+ volts at the power wire to the CDI with the key on. No power could indicate a bad ignition switch, fuse, or wiring issue.
• Ground – Inspect the ground wire and connection to chassis. Clean any corrosion and retest.
• Coil Wires – Check that both CDI outputs to the coil have 12V pulsed when triggering the ignition. No voltage usually means a bad CDI box.

Intermittent Spark

An intermittent spark that cuts out occasionally can be caused by:

• Loose Wiring – Check all wiring connections from the CDI to the pickup, ignition coil, battery, and switches. Wiggle the wires while running to find loose spots.
• Weak Trigger Signal – A pickup coil starting to fail can give weak inconsistent pulses. Replace the pickup if signal is out of spec.
• Defective Pickup – Cracked pickup coil insulation or loose magnets on the flywheel can cause misses.

Weak Spark

A spark plug that fires but is weaker than normal can lead to poor starting and performance. Potential causes include:

• Fouled Contacts – The pickup and ignition coil contacts inside the CDI cap can become dirty or corroded over time. Clean or replace.
• Low Battery Voltage – Weak battery output will result in a lower spark voltage. Recharge or replace the battery.
• Damaged CDI – Internal electronic components in the CDI box can wear out over time, reducing spark energy. May need a new or refurbished CDI unit.

By methodically testing each part of the system, you can zero in on what’s causing spark problems with your CDI ignition.

CDI Ignition Theory and Operation

To really understand CDI systems, it helps to know how they work under the hood:

The main purpose of any ignition system is to generate a high voltage spark to ignite the compressed fuel-air mixture in the combustion chamber.

In a CDI system, here are the key stages in creating that spark:

1. Trigger Signal

The trigger coil or pickup mounted near the flywheel generates an AC signal as the magnets pass by. This signal is usually between 0.4-2.0V AC.

2. Signal Amplification

The CDI box contains transistors that amplify the trigger signal from the pickup coil up to around 400V.

3. Energy Storage

Inside the CDI are one or more capacitors that charge up to high voltage during the dwell time between sparks.

4. Voltage Discharge

When the amplified trigger signal reaches the threshold, the CDI triggers its internal SCR or thyristor switch which dumps the capacitor’s stored energy into the coil primary.

5. High Voltage Induction

As the current rapidly collapses in the ignition coil primary, it induces a high voltage spike up to ~30,000V in the secondary which arcs across the plug gap.

This quick capacitor discharge is what creates the hot, intense spark in a CDI compared to a lower current spark in traditional ignition systems.

Conclusion

In this complete guide, you’ve learned what a 6 pin CDI system is, how to read the CDI wiring diagram, troubleshoot common problems, and understand CDI operation.

The key takeaways are:

• The 6 wires of a CDI connect the power, pickup trigger, ground, and ignition coil.
• Trace each wire in the wiring diagram during troubleshooting.
• Use a multimeter to test trigger, power, ground, and coil connections.
• Know the spark generation sequence including signal trigger, amplification, energy storage and discharge.

With this knowledge of 6 pin CDI wiring diagrams, you can quickly diagnose issues with your CDI ignition and get your motor running smoothly again. Riding is more fun when you understand how your vehicle works under the hood!