Insert meat thermometer into leg of pork, making sure it does not touch bone or fat.
Prepare fire in a covered grill.
Place pork on grill.
Cover and cook over low coals 4 1/2 hours; turn occasionally.
Baste with sauce.
Cover and cook 2 hours or until thermometer registers 160° (medium).
Baste frequently with sauce.
Let stand 10 to 15 minutes before slicing.