Duty cycle and dwell testing

[joe912/62]

The voltage fluctuates, that's a screen shot from the video I took.
Here is another screen shot at 12.16v. Should the voltage fluctuate like that?

[joe912/62]

To do any adjustments do you leave the oscilloscope connected and adjust the 3mm Allen screw
in the sensor plate? What range would it need it to be so I am within range or would I need to get a CO2 reader to test what's coming out of the exhaust.
Thanks

[AndrewCologne]

For setting CO via duty cycle all has been explained here where you took part :-):
Using Oscilliscope to Set Duty Cycle