Complex sentence: Gaston Rahier won the Dakar on a R80G/S in 1984 and then again on a larger 1000 cc engined R80G/S in 1985.
Split into simpler sentences: Gaston Rahier won the Dakar on a R80G/S in 1984. He repeated his success on a larger 1000 cc engined R80G/S in 1985.