i bought a brand new ybr 125 two months ago, rode it at 5,000 for about 100 miles, then i was sitting at 7-8000 on my commute to work due to high speed roads, bike now has 2,000 miles on it (i do a lot of commuting lol!) and its runnning sweet as a nut, have changed the oil two or three times though and run it on good castrol oil