Step 1

In a large bowl, mix barbeque sauce, teriyaki sauce, beer, garlic, ginger, onion, black pepper, and salt. Place the roast into the marinade, cover and refrigerate for six hours, turning often.

Step 2

Preheat an outdoor grill for indirect heat. Remove the roast from the marinade, and pour the marinade into a saucepan. Bring to a boil, and cook for 5 minutes. Set aside for use as a basting sauce.

Step 3

Thread the roast onto a rotating barbecue spit above indirect heat. Cook the roast for two hours, or until the internal temperature of the roast is at least 145 degrees F (63 degrees C). Baste often during the last hour with reserved marinade.