The throttle cable has one end that is the same as a brake cable. The other end that goes on the carb slide will need to me made. Follow Norm's post and it's quite easy. The OEM cable was far too long to use with the thumb throttle and even with all adjustments used to take up the slack, only allowed for maybe 1/2 throttle.
On the thumb throttle, I dremeled the opening where the cable inserts into the opening until the adjustment screw from an extra brake lever would slide in. Once the thumb end of the cable was securely attached in the housing, I made the carb end approximately 49mm off the end of the cable housing. If I recall, cable length on that end was about 49mm and the actual barrel length was 5mm. Use a spare brake line for the modification so that you can go back to stock set up if you don't like it or it doesn't work.
Kill switch is a simple momentary push button switch from Radio Shack mounted to an old rear seat post reflector holder.
Hope it makes sense.