I have a 2001 MZ Skorpion and I don't think the previous owners ever adjusted the rear suspension. It seems stuck or something.
I got the spanner wrench and it does nothing...actually I pulled so hard on it I messed up the nerves in my hand. (Now I have no feeling in one of my finger tips).
I have also tried putting some WD-40 on it to make it turn easier and even tried using a sledge hammer and screwdirver to forcefully break it loose, but nothing.
Any suggestions?