Motorcycle Repair: starter switch, starter switch, electrical diagram

Question
Hello - hope u can help me....  took apart apart handle bar assembly to repalce handlebar.(72 cb 500k) I see ur answer as to how starter button works by grounding. My problem is, I need to know where & how the yellow/red wire attaches. Does it solder on to the bottom of the starter button assembly? Also, there is a small metal plate with a hole on one end that fell out when I disassembled and cannot determine what it is for and where it goes?  I am at a loss, as i have had every friend i know look at this thing and we cannot figure it out.  Right now, if I allow the yellow/red wire to touch the handle bar, the starter engages.  Thanks for taking the time.   Mike

Answer
Without a proper electrical diagram of your bike in front of me, it is impossible to help you on this one. However, I did a search online and found one that I will refer to and hope it is accurate:

http://www.sohc4.net/index.php?title=CB500#Wiring_Diagrams

According to the diagram, the red/yellow wire should attach to a terminal on the switch itself. However, the diagram doesn't tell me HOW it attaches. Your best bet is to go to your local bike junkyard and look at another CB500 to see how the wires attach to the button.

When you touch the red/yellow to the handlebar you are bypassing the starter switch, which is why the starter will crank over. Don't do that. :-)

The piece of metal that fell out of the switch is probably a wire clip to hold the wiring in place so it doesn't get pinched when the switch housing is clamped together. There should be a very small post with a threaded hole in it that the screw, which is probably lost now, threads into through the hole in the plate.