Don't be vague. This isn't the subject for vague. Tell him exactly what WILL happen if he drives it with the kickdown unattached or adjusted incorrectly. This isn't a Ford or Chevy. It will burn the transmission SLAP UP if it is driven with the kickdown not hooked up or adjusted incorrectly. That linkage controls throttle pressure to the transmission and must be installed and adjusted correctly BEFORE you ever drive it.