I have a 12 with 1100 miles 26 inch dirt commanders stock everything else. When I start the engine, sit idling on an incline, or run it real hard down the trails the timing chain has started to chatter. Once I get it on level ground idling it will quiet down to normal. I have searched and haven’t seen this as a common issue. I just services all fluids and filters, bushings, and bearings. I might have 200 miles since all that was performed. Oil level is still at the top of the normal mark.