I suggest you look at the plug, do plug chop, see if running lean. I think OK to run hard if not too lean. I turn approx 10,000revs fairly often, but not for long. I don't worry about it much, but will wear out engine faster. These engines are fairly easy and cheap to rebuild IMO. When cruising, I like to keep it around 9,000revs or below, with my CVT setup is approx 45mph, a good speed for where I ride.