As a general rule of thumb, grill boneless, skinless chicken breast halves over Direct Medium heat for 8 to 12 minutes or until the juices run clear and the meat is no longer pink in the centre, turning once halfway through grilling time.
Grill bone-in breast halves over Indirect Medium heat, bone-side down, for 30 to 40 minutes or until the juices run clear and the meat is no longer pink in the centre. If you like a crispy skin, you can place the breasts skin-side down over Direct Medium heat during the last five minutes of grilling time.
Whole chicken and turkey is safely cooked when the juices run clear and it reaches an internal temperature of 170ºF in the breast and 180ºF in the thickest part of the thigh.
When taking the temperature of a whole bird, be careful not to let the thermometer probe contact bone. It could lead to a false reading.