Hi I'm new to this forum I have a 2008 canam ds 450 I have a bent exhaust valve the piston and the valve hit each other the timing is right on the money what could have caused this and after removing the head I brung my piston to top dead center and the piston is a little less than 1/8 th inch from being flush with the top of cylinder is this normal or did it bend my connecting rod a little bit