Preheat the smoker to 275°F.
Place the chicken on your smoker breast side up, and cook for about 2 hours.
After the first 45 minutes, check on the chicken, and give it a spray of cooking oil or butter to help the skin crisp up.
After 1.5 hours, rotate the chicken so that it cooks evenly and give it another spray or coating or cooking oil or butter. Check the temperature at this stage, it should read around 140°F for the breast, and around 150°F at the thigh.
After about 2 hours, it should read 165°F at the thickest part of the breast, and 175°F at the thickest part of the thigh (make sure that the thermometer is not hitting a bone to get a correct reading). That's when the chicken is ready to come off.
Remove the chicken from the grill and let it rest for 20 minutes to allow the juices to redistribute before carving and serving.