Removing the advancer weights/plate

   So, one of the pickups on the DYNA S which has worked perfectly on my '80 Z1R for the last 12 years has bitten the dust.  I ordered a new Dyna S, which looks slightly different
than the old/current one.  Here's probably an ignorant question- how do you remove the 13mm bolt holding the advancer mechanism in, in order to install the new rotor?   The bolt used to turn the 
crank is 17mm and pretty thin so putting a wrench on it to hold the crank while loosening the 13mm end bolt doesn't leave enuf room  for a wrench to bite.  Wish I could remember
what I did last time!  There are some vids on line but the ones I watched don't show removal of the bolt...

sorry abt that & thanks in advance-

bill 

I don't know how your setup is but I always used a socket for the 13mm bolt and the 17mm wrench to hold the nut like you did. This is what worked for me when removing my timing advancer.