Yamaha Motor, the world's second-largest motorcycle maker, said on Thursday that its quarterly earnings were ahead of target because demand surged in Asia and the US market was firmer than expected, Reuters reported. According to the news agency, group revenue for the April-June first quarter climbed 3.3% from a year earlier to 257 billion yen ($US2.14 billion) and, with motorbike sales more than doubling in countries like Vietnam and Thailand and models like its 600cc YZF-R6 sports bike well received in the United States, Yamaha said net profit zoomed to 8.7 billion yen, 24% ahead of its target.