A drop in net sales, an appreciating yen and the fallout from the March 11 earthquake and tsunamis in Japan contributed to a 4.6% drop in profit for Yamaha Motor Co. over the second quarter of 2011.

Over the quarter ended June 30, 2011, Yamaha saw a 5.9% drop in net sales compared to the same period in 2010.Yamaha reports sales of 344.5 billion yen (US$4.48 billion) over the second quarter, compared to the 366.3 billion yen (US$4.77 billion) reported in the same quarter in 2010. Yamaha’s second quarter net income totaled 15.5 billion yen (US$201.6 million), a 4.9% drop from the 16.2 billion yen (US$210.7 million) reported last year.

Despite the second quarter numbers, Yamaha is still up for the year, reporting a first half net profit of 29.0 billion yen (US$377.3 million), a 21.8% improvement from 2010’s net profit of 23.8 billion yen (US$309.7 million).

Motorcycle sales generated net sales of 242.5 billion yen (US$3.15 billion), a 6.2% year-on-year decrease from 2010. North American sales generated 9.8 billion yen (US$127.5 million) over the second quarter, a 19.0% decrease from net sales of 12.2 billion yen (US$158.1 million) reported in the second quarter of 2010.

Yamaha sold 1.78 million motorcycles over the second quarter, a 5.0% decrease from the 1.87 million units sold in the same period of 2010. North American sales dropped to 15,000 units from 18,000 units, while Europe (-22.0%) and Asia (-6.0%) saw even larger decreases in sales. According to Yamaha, new exhaust regulations in China had a negative impact on sales in Asia. Yamaha did report increased sales in Japan, Central and South America, and other markets however.

For the y ear,Yamaha raised its net profit forecast to 35.0 billion yen (US$455.1 million) from the previous forecast of 20.0 billion yen (US$260.1 million). If that holds true, it would nearly double the net profit of 18.3 billion yen (US$238.0 million) reported from the 2010 fiscal year.