If the unit is a CFI, {cleanfire} unit, unplugging the complete kill switch, all three wires, unit will not run, if you just unplug the single wire to the button only will and leave the other two wires, one ground and the other goes through the little pin switch in the throttle lever housing to the TPS, unit will run but have no kill button. If we unplug all three wires, coming from switch, unit has NO spark. All Cleanfire units CFI-2 or CFI-4 work the same. Hope this helps your question. If you unplug complete plug and try to start unit, and then hook to Digital Wrench, "Throttle Stuck " error will come up in Historic Codes, if still unhooked when scanned, will come up as a "Current Code". Hopes this helps..