sunbird schematics needed

i have a sunbird scooter i bought used and when i turn on key switch it runs at full speed (wiich is pretty fast lol) it has a and b on key switch. At this time when i turn it to (a) it is off. when i turn it to (off) it goes half speed. When i turn it to (b) it runs full speed. anybody have a schematic for the wiring? I also replaced the the controller and throttle. if i bypass key switch still same problem. I need help please.