One to one and a half hours is about the time it takes to smoke and cook the barbeque chicken skewers.  Smoking times will vary from grill to grill.  The size of the chicken pieces, the outside temperature, and the number of times that you open the smoker door will affect the cooking time.  If you would like more smoke flavor on your chicken kabobs start at a lower temperature such as 225°F to 250°F until the chicken pieces reach in internal temperature of 150°F.  Add the BBQ sauce, turn the grill temperature up to 400°F, and continue smoking until a 165°F temperature is reached on the kabobs.