A whole turkey can be grilled right on the cooking grate over indirect heat, but the advantage of using a rotisserie is that the bird slowly self-bastes as it rotates and absorbs the flavors of the fire. To ensure that the turkey stays in place as it turns and cooks uniformly, use butcher’s twine to truss it into a compact shape. Then secure the turkey on the spit, making sure it is centered as evenly as possible. This will put less strain on the motor. Always preheat the grill first. When ready to cook, set the spit in place, put a disposable foil pan underneath the turkey to catch the drippings, turn on the motor, and close the lid.