I have been caught out by CDI ignitions, thinking they were not working when I could not see the spark outside on a sunny day. CDI's have a needle fine spark that is difficult to see. This may not be your problem but try turning the lights off in your workshop.
The kill switch usually closes to ground, on some cheap ones the button can sometimes cock over and not open properly when released as well.
The kill switch usually closes to ground, on some cheap ones the button can sometimes cock over and not open properly when released as well.