Corona stains are caused by what?

• Oil particles being stuck to the ceramic by high voltage

• High voltage burning the ceramic

• High voltage leaking from the terminal to the shell

• High voltage leaking from the shell to the terminal

What is the purpose of the ceramic insulator in a spark plug?

• To prevent high voltage from shorting to ground

• To remove heat from the combustion chamber

• To increase the surface area voltage has to travel to ground

• To prevent flashover

What are the two main jobs of a spark plug?

• To ignite the air/fuel mixture and to remove heat from the combustion chamber

• To prevent pre-ignition and to increase horsepower

• To dissipate heat and to seal the combustion chamber

• To generate the correct amount of heat and to prevent fouling

What does the heat range of a spark plug determine?

• The temperature of the plug's firing end

• The resistance between the terminal and the metal shell

• The gas volume around the insulator nose

• The required coil voltage

What happens if the voltage required to jump the gap of a spark plug is greater than the resistance between the terminal and the metal shell?

• Flashover occurs

• The plug will foul out

• The plug will melt and pre-ignite

• The plug will not seal the combustion chamber

What determines the type of seat required for a spark plug?

• The cylinder head

• The insulator nose length

• The materials/construction of the center electrode and porcelain insulator

• The gas volume around the insulator nose

What is the purpose of a crushable gasket in a spark plug with a flat seat?

• To create a seal between the plug and combustion chamber

• To remove radio frequency interference

• To prevent pre-ignition

• To increase the surface area voltage has to travel to ground

What is the purpose of a resistor in a spark plug?

• To remove radio frequency interference

• To increase horsepower

• To prevent flashover

• To seal the combustion chamber

What is the purpose of the core in a spark plug wire?

• To conduct the charge needed to fire the plug

• To add strength and provide EMI suppression

• To protect the core against heat

• To reduce resistance and prevent EMI/RFI

Why is routing spark plug wires correctly important?

• To avoid inducing voltage in other wires and causing engine damage

• To prevent flashover

• To increase the surface area voltage has to travel to ground

• To remove heat from the combustion chamber