The 12 mm bolt has right-hand thread.
Never try to turn the crank on this engine side.
For turning the crank always remove the alternator cover on the right.
@PhilipC 1891 wrote:
Help much needed! I need to remove the advance/retard mechanism for the end of the crank (CB1100RB). Is the 12mm securing bolt left-hand thread? I note it is a different part number to the 900F/ 1100F?? Any ideas? The cam turns freely so I guess there is a woodruff key that has sheared? Help much appreciated.