My '13 had the same problem. First ride on the dirt, 900km. Get home & give her a check over & i find the engine dusted. Because i had drilled holes in the top cover, KTM Australia/Austria decided that was the cause & wouldn't pay to fix the engine. What a bunch of ****. I did however get a new airbox & piston out of them, & all this because i spoke directly with KTM Australia. My local dealer is useless.