ELECTRONIC IGNITION: Modern ignition in which electrical pulses are generated electronically, usually by transistors controlled by sensing devices, without the use of mechanically actuated breaker points.
IGNITION TIMING: The process of setting the time that a spark will occur in the engine combustion chamber relative to piston position usually a few degrees before top dead center of the piston during power stroke. The correct ignition timing will change slightly due to the RPM of the crankshaft. Modern motorcycles engines are controlled by an engine control unit also known as ECU or CDI, sometime referred to as "the black box". Among other processes this computer is used to control the timing throughout the engine’s RPM range. Older engines that use mechanical spark rely on centrifugal force, rotating weights and springs advance the timing allowing the spark to occur earlier during high speed.
SPARK PLUGS: Spark plugs must in addition to firing a spark, also remove heat from the combustion chamber. This is accomplished by allowing heat to transfer through the insulator material and metal housing. The heat is then transferred to the cylinder head hence cooled by the water jacket of the cooling system. A spark plug’s heat range is its ability to dissipate heat. The “colder” the plug, the more heat it can channel out of the combustion chamber. In a performance application, colder heat ranges may be necessary to handle the extreme temperatures brought on by higher compression ratios, forced induction, and high RPM’s. While “Colder” plugs may seem to be the way to go, please remember that the spark plug must achieve its “self-cleaning” temperature where it can burn off fuel and carbon deposits. Otherwise, the plug could “foul out” where it is prone to misfiring and poor acceleration. A plug that is too “hot” can overheat, also causing power loss, detonation, pre-ignition, and possible engine damage. A good, general rule of thumb is to start with the factory recommended heat range. If your doing a lot of high performance modifications to your motorcycle, you may want to go to the next colder plug.