Butter mixture: In a small saucepan over medium heat, combine butter, water, and bouillon powder and warm just until the butter has melted. Remove from the heat, taste for seasoning, and adjust with bouillon powder if needed. Transfer to a tall, narrow container (so it's easier to fill the injector) and let cool to room temp.
Dry turkey off. Fill injector with butter mixture and inject the turkey, 1-ounce at a time. Inject one half breast 3 times (different areas, same hole). Inject each thigh 1 time.
Season turkey liberally with garlic salt and pepper. Tuck wings behind the bird. Set aside at room temp 1 hour, or in the fridge up to 24 hours before cooking.
Get smoker to 250F. Let wood burn off 5-10 min. Load the turkey breast-side up onto rack. If temp drops to 240F, add a little more wood and charcoal.
After 2 hours, spray turkey with apple juice. After 3 hours, add small applewood chunk. From then on, it's pecan and charcoal the rest of the way. Continue smoking, spraying with apple juice everytime you check the turkey or wood. At 4 hours, check internal temp of thigh (165F).
Once turkey is cooked, baste it with melted butter just before it comes out of the pit. Let rest at least 30 min-1 hour before carving.
