I recently got my hands on my new KTM Duke 390 2017 , it has hardly covered 100 km and there is a weird sound coming from engine @ 5000-5200 rpm after engine gets warm(ie. after covering 5-6 kms). This vibration is only present in this particular rpm band. I told my ktm dealer about this problem but they are unable to find the cause of this problem. What should i do now. This is very disappointing. Has someone noticed the same problem in his bike???