In a shallow glass dish, mix the oil, lime juice, lime zest, garlic, oregano, red pepper flakes, salt, and black pepper. Add chicken, and turn to coat. Cover, and marinate in the refrigerator for 1 hour, turning occasionally.
Preheat grill for medium-high heat.
Lightly oil the grill grate. Drain and discard marinade. Grill chicken for 6 to 8 minutes each side, or until juices run clear.
