In small bowl, mix all ingredients except turkey. In shallow glass dish, place turkey. Pour half of the plum mixture over turkey; turn turkey to coat. Cover dish; refrigerate 30 minutes, turning once. Reserve remaining half of plum mixture to serve with turkey.
Heat gas or charcoal grill for indirect-heat cooking. Remove turkey from marinade; reserve marinade for basting.
Place turkey on grill for indirect cooking. Cover grill; cook over medium-high heat 25 to 30 minutes, turning and brushing occasionally with reserved marinade, until juice of turkey is clear when center of thickest part is cut (170°F). Discard any remaining marinade. Heat reserved plum mixture. Serve with sliced turkey.