In a bowl, mix the soy sauce, brown sugar, lemon juice, vegetable oil, ginger, and garlic powder. Set aside some of the mixture in a separate bowl for marinating during cooking. Pierce the pork chops on both sides with a fork, place in a large resealable plastic bag, and cover with the remaining marinade mixture. Refrigerate 6 to 8 hours.
Preheat the grill for high heat.
Lightly oil the grill grate. Discard marinade, and grill pork chops 6 to 8 minutes per side, or to desired doneness, marinating often with the reserved portion of the marinade.
