Lambr62 wrote:Hi,
I have two lines on my flywheel at one of the window positions and a white line on stator plate pick up box. When i line up BTDC timing position should the white line on pick up sit in the middle of these two lines at the 5 o'clock window position or should one or the other of the two lines on the flywheel window be in line with pick up white line? Slightly confused if it is the latter as why should you need two lines on fly wheel window position? Thanks in advance for any help.
The CDI has to differentiate between what is sees as electrical noise (misfire) and what is a genuine triggering requirement. Every time one of the magnets on the flywheel passes over the trigger coil it induces a voltage ( a single pulse)
We only want the CDI to fire from one of those magnetic positions and so the laminates of the stator are so designed at one position to firstly generate a positive pulse which then rapidly turns to a negative pulse of no more than +/- 5v. As the voltage passes through the zero crossing point this is when it fires the Thyristor within the CDI to discharge the capacitors stored energy into the primary side of the ignition coil.
It is normal for CDi's to show a retarding effect as the engine revs rise. This is because the time it takes from triggering to spark occurring is a relative constant ( there are some other issues which can affect this but for the purposes of this discussion we can say it is a relative constant) and the distance the piston has moved within this constant time is a variable.