When it comes to working on bikes, there is a lot to know about anything from suspension systems to carburetors to alternators. Knowing each of these parts is essential, but it’s also crucial to comprehend how they interact.
The ignition system on a motorcycle is one of the most crucial components. An ignition system’s performance is essential for a motorcycle to run. Numerous problems may arise if it breaks down, which is why experts who can diagnose these systems play such a crucial role.
Consequently, what are motorbike ignition systems and how do they operate? Learn more about the parts of the ignition system and how they interact to produce the spark that engines require in the following paragraphs.
What Is An Ignition System For A Motorcycle?
The primary function of a motorcycle ignition system is to provide the spark that ignites an air/fuel mixture inside the motorcycle engine.
For the compressed air/fuel mixture to burn correctly and the expanding gases to push the piston down the cylinder, a spark must happen when the piston is nearly at the peak of the compression stroke. The ignition system must not only provide the high voltage required to ignite the spark plug, but also send the spark at precisely the proper moment.
One of three distinct but linked electrical systems on a motorcycle is the ignition system. The charging system and the starting system are also present. The starter motor, ignition switch, and battery are all parts of the starting mechanism. The stator, rectifier/regulator, and battery are all components of the charging system.
A Quick History
Controlling spark distribution in an engine is a function of both point and electronic ignition systems. The transition from a mechanical system to an electronic one is represented by electronic ignition. Let’s define the terms and discuss why they need to evolve before moving on.
Ignition Points For Motorcycles
A mechanical/analog way of regulating, when the coil-generated spark is transmitted to the cylinder, is by using ignition points. Points are useful until they are not. For the system to operate properly, maintenance is essential. Regular intervals, often yearly, are necessary for lubrication, cleaning, and filing the points.
A mechanical switch is a point, a rotating cam regulates the switch’s opening and closing. The 90-degree rocker arms open and close the switch when the engine-speed center shaft rotates. This completes the circuit and breaks it, sparking the ignition coils.
Ignition By Electronic
Manufacturers of automobiles and motorcycles switched to electronically controlled ignition primarily for two reasons: dependability and performance, particularly at high RPM. Although electronic ignition was first used in the 1960s, it wasn’t widely adopted until the 1970s.
Modern motorcycles typically use one of three different types of electron ignition systems:
- AC-CDI – Alternating Current Capacitor Discharge Ignition
- DC-CDI – Capacitor discharge ignition with direct current.
- DC-TPI – Transistorised Pointless Ignition using Direct Current.
These systems cause the spark plug to ignite at precisely timed intervals regardless of the voltage type, alternating or direct, enabling the motorcycle to run. Additionally, depending on engine demand, these ignition systems can advance or retard ignition timing.
Motorcycle CDI Ignition System
You’ll frequently hear about something called a CDI box, or capacitor discharge ignition box when it comes to ignition systems. In essence, a CDI box regulates the ignition system of a motorcycle by initiating the ignition and combustion process. The spark plug is ignited by a pulse of electricity from the motorcycle battery that travels through the CDI box.
Modern ignition systems also have the following additional components in addition to the CDI box:
- Battery
- Coil
- Spark plugs/spark plug wires
- Switch
- Pickup coils or crank position sensors
Despite being quite dependable, certain parts can fail, which can prohibit a motorcycle from operating as it should. An experienced technician can quickly and accurately test and troubleshoot ignition system components.
A motorbike ignition system’s two main goals are:
- Creating the voltage required to ignite the mixture of gasoline and air.
- Supplying the engine with a spark at the ideal moment.
How does A Motorcycle’s Ignition Coil operate?
How is this problem solved if a motorcycle battery only produces 12 volts, yet 12 – 20,000 volts (or more) are required to jump the spark plug gap and ignite the air/fuel mixture?
In motorcycles, a coil is used to step up the battery voltage to the appropriate level. An ignition coil for a motorcycle is a transformer made up of two different wire coils wound around a central post.
A few twists of heavy-gauge wire make up the primary winding of the coil. The much finer wire is wound numerous times in the secondary winding. This two-winding technique significantly raises the voltage until it reaches the required level to ignite the spark plug.
Even when the wires are not connected, the phenomenon known as mutual induction occurs when the voltage in one wire causes voltage in another wire. The ability to change the characteristics of power, such as a considerable increase in voltage inside the coil, is what mutual induction is most crucial for.
Timing Is Critical
When given to the engine at the incorrect time, a spark of even the highest voltage is ineffective. An engine that is not properly timed will, at best, function poorly, and, at worst, it will cause damage to the engine itself. Computer inputs used to manage the timing of new motorcycle engines include:
- Motor RPM.
- Throttle opening percentage.
- Temperature of the engine.
The exact moment to release a spark of peak performance varies, which further complicates issues. Timing the ignition is not a task that can be set and forgotten. The spark plug needs to fire earlier about the piston’s movement within the cylinder as engine speed (RPM) increases. To “advance” ignition time, the spark must be delivered sooner; to “retard” ignition timing, the spark must be delivered later.
Before electronic engine management, older motorcycles employed straightforward mechanical systems to advance or retard time by engine needs.
Although these simple devices functioned, they were constrained by the maintenance they required and their inability to meet ever-stricter emissions standards. Today’s electronic ignition systems automatically modify the timing of the spark plugs to respond to various engine demands.
Stick coils, like the one below, are integrated devices that sit atop each spark plug. Older designs’ hefty gauge, high-voltage plug cables are no longer necessary as a result.
Ignition System Troubleshooting
When diagnosing or repairing a motorbike ignition system, where does a technician begin?
Any diagnostic technique must begin with a battery that is known to be in good condition. There is no guarantee that a headlight-illuminating battery will provide the voltage needed to start and operate a vehicle. Before addressing issues with the ignition system, a technician may charge and test a battery or they may just install a brand-new, tested battery.
Other typical ignition system examinations include:
- Checking the continuity of the pulser coil.
- Measuring the voltage output from the pulse coil.
- Examining the ground wires, switches, and fuses.
- Checking the resistance of the ignition coils on both circuits.
CDI box: This can be challenging to diagnose. Installing a new CDI box could assist in locating the issue if everything else is in order.
How Does This Affect Motorcycle Technicians?
Components of the ignition system, together with the starting and charging systems, are essential for a motorbike to operate safely and reliably. Diagnoses of motorcycle ignition system issues can be challenging, especially when compared to mechanical faults that may be obvious to the naked eye.
There is a high demand for technicians with knowledge and expertise in this field. The time you invest now learning how to diagnose, repair, and troubleshoot ignition system problems can pay you greatly in the future in your profession.
