I have searched and did not see a post or sticky pertaining to the adjusting of the Huasheng's valves. I would like to know what to do to them and how to do it as I have no experience with this. What tools are needed? Can someone please chime in on this, maybe it would make a good sticky. I am hearing some noise and I believe its the valves, not sure though. Sound like a metallic chattering noise. Thanks for any help.