Motorcycles have many systems that all together create a perfectly working machine. A motorcycle ignition system is undoubtedly one of the crucial systems of your motorcycle, and in this article, we will explain everything about the ignition system and how it works.
So how does a motorcycle ignition system work? A motorcycle ignition system is a motorcycles system whose primary purpose is to create a spark through the spark plug that ignites the air-fuel combination in your motorcycle engine. By doing so, it starts your motorcycle and gets it ready for the ride.
Now let’s take a deeper look at your motorcycle ignition system and all the things related to it, as well as everything you might find interesting and valuable about your motorcycle ignition system.
Table of Contents
What Is a Motorcycle Ignition System?
A motorcycle ignition system is a vital system for igniting your motorcycle. The system creates the spark which fires the air-fuel mixture and prepares the motorcycle for a ride.
The ignition system needs to create a spark when the piston is near the top of the compression stroke because the compressed air-fuel combination needs to burn correctly, which will make the expanding gases press the piston down the cylinder.
What is interesting about the ignition system is the precision that all of this needs to be done because the ignition system produces a high voltage that is used to ignite the spark by firing the spark plug. The system needs to send the spark at the perfect time.
There are three separate but related electrical systems on your bike, and the ignition system is one of them. Along with the ignition system, there are the charging and starting systems.
- The charging system is built of the battery, stator, and rectifier (regulator)
- The starting system is built of the battery, starter motor, and ignition switch
Electronic ignition systems and points are in charge of controlling spark delivery to your motorcycle engine. Electronic ignition is a modern system that was made as the successor to the mechanical system, and this shift made a lot of difference in the ignition system.
Before I continue about the ignition system, let me first explain what points are and why they are significant for the ignition system.
Here is a great article about How Do Motorcycle Spark Plugs Work, so click on this link if you want to learn more.
Motorcycle Ignition Points
Ignition points are an analog (mechanical) method used to control when the previous coil-created spark needs to be sent to the cylinder. Motorcycle ignition points are vital for the ignition system to work correctly, so they must be maintained perfectly.
Points maintaining includes cleaning and filling the points, setting the gap, and lubricating them. All of these need to be done at regular intervals that are specific for every motorcycle. Sometimes there is even a chance that the points need to be maintained yearly.
Motorcycle ignition points are mechanical switches, and a spinning cam controls their opening and closing.
Electronic Ignition
The electronic ignition system is used in both motorcycles and cars, and the two main reasons for that are performance and reliability, especially on higher RPMs. Electronic ignition dates to the 1960s, but it was widely accepted in the 1970s.
Modern motorcycles have three main types of electronic ignition systems, and they are:
- DC-CDI: Direct Current, Capacitor Discharged Ignition
- DC-TPI: Direct Current, Transistorized Pointless Ignition
- AC-CDI: Alternating Current, Capacitor Discharged Ignition
All of these systems, regardless of the voltage type, whether direct or alternating, cause the spark plug to ignite at the perfect intervals, making your bike start and run.
Another interesting fact about these ignition systems is their capability to retard or advance the ignition timing, which depends on your motorcycle’s engine demands.
CDI Motorcycle Ignition System
CDI box is what you will most often hear about the ignition system. CDI box stands for capacitor discharge ignition box, and it starts the combustion and ignition process, and that way controls the motorcycles ignition system.
A voltage pulse is created in the motorcycle’s battery and sent through the CDI box to ignite the spark plug. There are some other parts of modern motorcycle ignition systems besides the CDI box, and they are:
- Coil
- Battery
- Switch
- Spark plug
- Spark plug wires
- Pickup coils
- Crank position sensors
Although these components are very reliable, they can fail and stop your motorcycle or prevent it from working correctly. If any of these problems happen, you can take your bike to a skilled technician who shouldn’t have any difficulties diagnosing the ignition system and detecting what is wrong with your bike. Taking your bike to a professional is the quickest, safest, and most reliable way to detect what is wrong and how to fix it.
Here is a great article about How to Change Motorcycle Spark Plugs, so click on this link if you want to learn more.
The motorcycle ignition system has two main objectives, and that is:
- Creating the proper voltage that is needed for igniting the air-fuel combination
- Sending the spark to your motorcycle engine at the precise time
How a Motorcycle Ignition Coil Works
To understand how the ignition coil works on your motorcycle, let us give you an example.
If your motorcycle battery creates 12 volts, and 12-20 or in some cases even more volts are required to jump the spark plug gap and also fire the air-fuel combination, how is this scenario solved?
An ignition coil is used on motorcycles to set the battery voltage to the correct range needed. A coil is a transformer made of two detached coils of wire that are wounded around the central post.
The primary winding of the coil is made of a couple of turns of heavier gauge wire, while the secondary winding is wrapped many times with finer wire. These two winding systems are important because they increase the voltage to the required level to fire the spark plug.
There is a possibility that a phenomenon called mutual induction happens, and what that means is that the voltage in one wire induces the voltage on another wire. It can happen even when these two wires are not connected. Mutual induction lets the characteristics of the power change, like a significant increase in the voltage inside the coil.
Why Is the Timing Important?
If the spark is delivered at the wrong time to your motorcycle engine, it won’t be effective even if it is the highest voltage spark delivered. The best-case scenario will be that a badly timed engine will have lousy performance, and in a worst-case scenario, a badly timed engine can get destructive to itself, which is the scenario that we don’t want to happen.
In modern motorcycles, the engine timing is controlled by a computer and uses data like:
- Percentage of throttle opening
- Engine RPM
- Engine temperature
The optimal time for a spark to be delivered varies, which means that ignition timing is not set at the specific measure, and that’s it. When a rider rides faster and the RPMs increase, the spark plug has to fire earlier than the piston’s travel inside the cylinder.
We will mention two terms that relate to spark delivery:
- Retard ignition timing refers to delivering the spark later
- Advance ignition timing refers to delivering the spark earlier
Before there was electronic engine control, old motorcycles had simple mechanical devices that were used to retard or advance time depending on the needs of the motorcycle engine.
These simple mechanical devices worked well, they were limited by their need for maintenance, and they were unable to fulfill demanding emission requirements. In nowadays modern electronic ignition systems, the spark timing is automatically adjusted to satisfy a range of demands of your motorcycle engine.
Every spark plugs top has stick coils that are all in one unit, and because of that, there is no need for the high-voltage, heavy-gauge plug wires that are integrated into the older versions.
How to Check Ignition Systems
Determining problems about your motorcycle ignition system is the first step that needs to be done before fixing it.
You need to start by examining the battery. There is no guarantee that a battery that powers your headlight has the voltage necessary for starting and running your bike. A skilled technician and even you can charge the battery and run a test before troubleshooting the ignition system, or you can just get a new battery and install it.
If you want to learn How to Change and Fix Your Motorcycle Battery, click on this link.
You can run many ignition systems tests, and these are the most common ones:
- Checking the pulser coil for voltage output
- Checking fuses, ground wires, and switches
- Checking the pulser coil for continuity
- Checking the resistance of ignition coil on both circuits
- CDI box, which can be challenging to troubleshoot. If everything else fails, changing the CDI box could help you determine the issue.
Ignition System Events
This image shows ignition system components and how they function and operate:
Here is a nice video explaining the motorcycle ignition system and how it works:
Final Thoughts
The ignition system is a crucial part that is responsible for proper motorcycle functionality, together with charging and starting systems. Knowing your ignitions system can help you with a lot of things such as diagnosing problems, understanding how everything works and what is the point of the system in the first place.
If you feel unprepared to determine the problem, don’t hesitate to call an experienced technician and ask him for a proper diagnosis and what needs to be done to repair the system.
I hope you liked this article and that you learned everything you need about motorcycle ignition systems.