Heres a quick idiots guide then
The fuel mixture is ignited before the piston reaches the top of the cylinder on the compression stroke. The fuel burns in such a way that it takes time for the flame to fan out. By the time it reaches the piston, the piston has already went past the top of the cylinder and on the way down, the flame kicks it in the arse to help it along.
The ignition angle is the angle in degrees ( of the crankshaft ) that the spark plugs fires at, usually measured in before or after TDC ( top dead center, when the piston is right at the top of the cylinder ). For the standard Pulsar the basic igntion angle at idle is 20 degrees before top dead centre.
In very simple terms ( this is an idiots guide ), when the crankshaft is at 0 degrees, the piston is right at the top of the cylinder, when the crankshaft is at 180 degrees, the piston is right at the bottom. The mixture on the pulsar is ignited at 20 before the top, if it was a scale of 360 degrees for one revolution then it would actually be angle 340 degress, but its normally expressed in 'degrees before zero' or BTDC.
Hope that helps...
