Spark Plugs
A spark plug is a small device used in petrol engines to ignite the air-fuel mixture inside the engine cylinder. It creates a small electric spark that starts the combustion which powers the engine.
Main Function
Produces a spark to burn the fuel and air mixture.
Helps the engine start and run smoothly.
Where Spark Plugs Are Used
Petrol cars
Motorcycles
Generators
Lawn mowers
Small engines
(Diesel engines do not use spark plugs.)
Main Parts of a Spark Plug
Terminal – Connects to the ignition coil or plug wire
Insulator – Ceramic part that protects the current
Metal shell – Screws into the engine
Electrode – Where the spark jumps
Signs a Spark Plug Is Bad
Engine hard to start
Poor fuel consumption
Engine misfiring
Weak engine power