I bought a new 2014 XC-F 350 in the fall. I studded some tires and have been winter riding 5-6 times this year. Bike is fantastic but it has started to have a weird rattle noise. If has under 10 hrs still. It sounds like a loose fastener like something is vibrating but everything is tight. The noise increases with rpm. You can't hear it at idle, only when you rev it. As well, it doesn't seem to do it when the motor is cold. I know the older cam chain tensioners were bad, but I don't know if that is my problem or if they are still bad in the 14's. I don't think the cold temps should affect anything with the fuel injection, but it does sound like a ping. Any thoughts?