I am using this bike since 2009. Has given no problems at all. It crossed 45000kms.
I use shell helix ultra oil 5w40. I change the oil at every 9000km or 3yrs as the cost for 1ltr is Rs 1200
My bike has become more efficient, its now smoother and had good pickup n mileage.The best part is about the maintenance we done have to worry much.