The nut should be a 30mm across flat size.
Get a good 30mm ring spanner.
Have somone else try to hold the drum in position from inside the m/c through the door.
position the spanner at the top and hit it with a hammer to shock it free the person holding will not be able to stop it turning but will add resistance to the hammer blow.
the nut is thread locked on so will be difficult but I managed ok with this method. The thread is a normal right hand thread so with the spanners at the top knock it anti-clockwise
PS the pully is also threaded onto the shaft so don't try to prise it of with screw drivers like I did for an hour!!!!
David Foster, May 2006
