In a large bowl combine water, salt, sugar, and corn starch. Add chicken, cover with plastic wrap, and refrigerate 30 minutes, but no longer than an hour.
PREHEAT GRILL:
Turn the gas grill on HIGH and close the lid. Preheat the grill for 15 minutes before putting the chicken on.
SAUCE
Add the olive oil, orange juice, onion, garlic, cilantro, oregano, chili powder, cumin, salt, pepper, lime juice, and lime zest in a blender and blend until a thick sauce forms.
PREP THE CHICKEN:
Remove the chicken from the brine, pat it dry with paper towels, and discard the brine. In a small bowl, combine the salt and pepper, then rub the seasoning over all sides of the chicken.
GRILL THE CHICKEN:
Scrape and oil the grill grates. Turn off all burners except the main burner, which should be set to medium-high.
Place the chicken on the hotter part of the grill and cook for 2-2 ½ minutes.
Turn the chicken over and brush with the sauce. Cook for 2-2 ½ minutes, until browned on the second side.
Repeat the turning and brushing process 2 more times, cooking for 2 minutes on each side.
Flip the chicken one final time and brush with the sauce. Cook for 1-3 minutes or until the chicken reaches an internal temperature of 160 degrees F on an instant-read thermometer.
Transfer the chicken to a serving plate, let it rest for 5 minutes, and then serve.