Coil is a unit that converts low voltage source (12V) of the battery as a source of high voltage (10kV). This high voltage necessary to produce a strong spark jumps the spark plug gap.
Coil has a variety of types, namely:
Type 1 Canister
This type has an iron core in the middle and secondary coil surrounds the iron core. The primary coils are on the outside of the secondary coil. Overall the components are assembled in a house in a metal canister. Sometimes canister filled oil (lubricant) to help reduce heat generated coil.
Moulded type coil is a type that is now commonly used. In this type of iron core in the middle, surrounded by the primary coil, while the secondary coil is on the outside. Overall assembled components are then wrapped in a machine (resin) to be resistant to vibration typically found in motorcycles.
Type coil molded into a popular option for resistant and robust construction. In multicylinder engines (cylinder many) are usually one coil serves two spark plugs because it has two high voltage wires from the secondary coil.
This coil type is the type of new and often referred to as coil rod (coil sticks). The large size and weighs less than molded coil and the greatest advantage is this coil does not require high voltage cables.
