How do you set the carbohydrates on a 1400 Intruder?

Normally you don't have to make adjustments on the carbs other than idle setting; if the carbs are running poorly and the motorcycle has set for more than 6 months unstarted with old fuel in it, then the fuel system (including the carbs)will probably need cleaning out. Making carb adjustments other than idle requires expertise and would recommend leaving that for the dealer or mechanic.