Thanks.
I already added resistor to limit current otherwise excessive current causes shutdown engine since CDI not getting required current.
I have traced spark trigger wire from engine coil (not ignite coil) this wire is going to CDI module.
I'm using this wire as tach signal. Now the idle speed is about 2000 RPM and it is stable if accel is not touched.
This is minimum setting with idle adjust screw below this setting engine start dying.
Now my concern is weather this idle RPM normal ? I hv read some where idle RPM should be 1000 -1200.
What would the reason for this almost double RPM display .
Do I further need pulses divide by 2 to get 1000 RPM on idle.