Hi guys, first of all, I was using the search function but did not find anything usefull. I have a 92' XR600R. The service manual that i have states that both intake valves and the left exhaust valve have to be adjusted in the TDC of the compression stroke. The the right exhaust valve 360 degrees later at the TDC. The tutorials that I've found all say that all 4 valves are adjusted at the same TDC of the compression stroke. Which one is true? Also, I have a PD8AF B carburetor. Can anyone tell me what these letters mean? I've bought this bike used and found that the main jet is 168 and the pilot 62. I think this is not standard but can't find any information about it. I also can't find which model my bike is (B,U,J,DK???)? Can anyone help?