Hello, I just purchases a brand new 2013 crf 50 for my little boy and it had, what sounds like, a bad wrist pin or lower end knock, plus tricky valves. It now had 45 minutes on it and sounds even worse! Has anyone else noticed something like this with the 2013s? We live a distance from the dealership, but I'm ready to return it as it has the warranty. Anyone else have a similar experience?