Grilled Tri-tip Roast

Prepare an outdoor grill for indirect heat, and lightly oil grate. In a small bowl, mix together the garlic powder, onion powder, pepper, and salt. Rub mixture all over the roast. Place the roast, fat side up on the hot grill with a pan underneath it to catch the drippings. Bake/roast for 4 to 6 hours, or until done. Check for doneness with a meat thermometer. Minimum temperature should be around 165 degrees F (78 degrees C).