Ignition Timing

During ignition of a mixture of gasoline and air is a time
of a spark plug spark some degree before top dead centre (TDC) at the end of the compression step. When the occurrence of spark
time must be determined appropriately so that you can burn
the perfect mix of gasoline and air in order to achieve energy
maximum.
After the mixture of fuel burned by fireworks, the
time required for fire to spread in the room
fuel. Therefore there will be a slight delay between the start
burning with the achievement of the maximum combustion pressure.
Thus, in order to obtain maximum output with the engine
combustion pressure reaches the highest point (about 100 after TDC),
the propagation of fire should be considered when determining
ignition timing.
Because requesting a time for propagation of fire, the
mixture of fuel - the air must have been burned before TDC. When
start of a burning mixture of fuel and air is
called the ignition time. So that when the ignition
can be adjusted with the speed, engine load and other
equipment needed to change (forward or rewind)
during ignition. One of them is to use
vacuum advancer and governor for the ignition advancer conventional.
In a motorcycle is usually called the (Automatic Timing Unit). ATU will
set during furtherance ignition. In the motorcycle with the system
conventional ignition (using platinum) ATU regulated
mechanics while the electronic ignition system ATU regulated
electronic. More explanation about ATU discussed in part I
(Type System ignition On Motorcycles).
When the ignition time moved forward too far, the maximum combustion pressure is achieved before 10o
after TDC. Because the pressure in the cylinder will become higher
from the burning time with the right mix for burning
air fuel that occurs spontaneously and ultimately will occur
knocking or detonation.
Knocking is an explosion that resulted in a wave
a surprise because the wage-pounding sound pressure and a large
going strong at the end of the burning. Knocking over will
cause the valves, spark plugs and piston burn. When the ignition
too forward can also cause the engine temperature becomes too high.
Meanwhile, when the ignition time retard too far then the maximum combustion pressure occurs will
after 10o after TDC (at which the piston has come down far enough). When
compared with the ignition timing is correct, then the pressure in the cylinder is rather low so that the engine output
decreased, and the waste of fuel and other will occurred. Ignition when the correct pressure can produce
optimal combustion.