Kevin not sure what old is any more but I have a Hawk 220VS and a 226VS Never had a problem with the back lever poping up. I do not have the barrel clamps. I have the newer ones. There is a flat spot on the lever and it lays flat on the triangle wedge all the way. Make sure. There should be no play in that cam when blade is tight. I really do not mess with that setting any more. My adjustment is when I place a blade in the bottom holder and install holder, I swing the top part of the blade into top holder and top of blade touches top of blade holder every time. If I have to switch to a different blade I usually have to cut some of the blade off to make fit just so I do not touch that back adjustment. Works for me. I will say this that lever works its way toward the arm and sometimes it will chatter against that. I placed a piece of foam rubber so this does not happen. That is about all I can tell you. You can tighten the bottom nut on the rod to make it more stiffer.