Spark Plug

A spark plug creates the required spark for igniting the fuel and air mixture in the combustion chamber which in turn allows the engine to run. It is shaped like a small cylinder.

Parts of Spark Plug
Basically, the spark plug consists of three parts which are assembled together to form an operational leak-proof unit.

• The insulator
• Electrode
• A threaded metal shell

Characteristics of Spark Plug

• The spark plug indicates the conditions of the engine.
• During operation, the plug must be hot enough to prevent fouling and cool enough to prevent pre-ignition and rapid erosion of the electrodes.
• Spark plug by itself does not create heat, instead it removes heat. It works as a heat exchanger

Functions of Spark Plug
The spark plug does two primary functions

• Ignite the air-fuel mixture.
• Transfer heat from the combustion chamber.
• Sparks turn fuel into working energy with the help of the electrical energy it carries.

A sufficient amount of voltage must be supplied by the ignition system to spark across the spark plug's gap. This is called "Electrical Performance."

Maintenance of Spark Plug

• Basically, spark plugs should be checked every 10,000 miles.
• Use a steel brush to clean rust and carbon.
• Spark plugs should be washed properly in a solvent and dry with compressed air.
• The insulator of paint, carbon and oxide that forms from fuel additives should be cleaned thoroughly.
• The electrode should be filed flat.
• The cylinder head threads and plug threads should be cleaned thoroughly.
• Be sure the spark plug cable fits the plug terminal snugly.