Insert spit rod through center of roast.
Adjust holding forks; test balance.
Insert meat thermometer near center of roast but not touching metal rod.
Soak hickory chips in water.
Place medium coals on both sides of drip pan.
Attach spit so roast is over drip pan; turn on motor.
Add damp hickory chips to coals; lower smoke hood.
Roast till meat thermometer registers 170°, about 3 hours.
After first hour, brush roast with a sauce made by combining the soy sauce, cooking oil, molasses, dry mustard, ginger, and minced garlic.
Let the cooked roast stand about 15 minutes before carving.