In a small mixing bowl, COMBINE oil, lime juice, tequila, cilantro, Triple Sec and salt; STIR until blended.
Lightly POUND chicken breasts to a uniform thickness; PLACE in a lidded, flat-bottomed storage container.
POUR margarita mixture over chicken; TURN to coat well; COVER; REFRIGERATE for at least one hour.
REMOVE chicken from marinade; RESERVE marinade.
HEAT grill to medium (about 350°); PLACE chicken breasts on grill; BASTE generously with marinade.
GRILL for 8 minutes; TURN; BASTE again; GRILL until done, about 8 more minutes.
Per Serving (excluding unknown items): 193 Calories; 18g Fat (93.8% calories from fat); trace Protein; 3g Carbohydrate; trace Dietary Fiber; 0mg Cholesterol; 134mg Sodium. Exchanges: 0 Fruit; 3 1/2 Fat.