My ATC200M has been making this ticking noise for quite some time. I am 99% sure it is NOT the timing chain. I think it is the valves ticking. I tried to adjust them but I think the clearance is too big because it was difficult to fit a flat bladed feeler gauge in there. What do you think?
Heres a link to the recording: http://vocaroo.com/i/s1yZZnQ8MlyF