For hot rodders, spark plugs are often nothing more than inspection tools that reveal whether an engine is running too rich, too lean, or just right. Street guys look for a nice tannish-brown tint on ...

For hot rodders, spark plugs are often nothing more than inspection tools that reveal whether an engine is running too rich, too lean, or just right. Street guys look for a nice tannish-brown tint on ...

A spark plug is a device that delivers electric current from the ignition to the combustion chamber of an engine to ignite the compressed mixture of air and fuel. All motorcycles, including those from ...