Roketa MC-54 250B valve adjustment Apr 27, 2011 21:44:03 GMT -5 Quote Select PostDeselect PostLink to PostMemberGive GiftBack to Top Post by DR J on Apr 27, 2011 21:44:03 GMT -5 Here is a video showing how to properly adjust the valves on a Linhai 257cc engine.Intake should be .003" or .0762mmExhaust .005" or .127mmwww.jclusa.com/uploads/Media/MP250A%20Valve%20Adjustment.wmv