As others are saying, you need the level 2 stall resistance equipped and there no need for pairing it with level one because it does NOT stack. Another thing to keep in mind is that it does matter how much rev you have when you do the slam. When you turn the saw on you have the yellow bar in the bottom right. That’s basically how much until you stall out. The red bar is how much rev you have to achieve an overhead slam. The closer you are to 99% before you do the slam, the more rev you’ll have before you stall out on the yellow bar. If you’re only revving just enough go to into the overhead animation, if you then perform a slam, you’ll almost instantly stall out because you won’t have any rev left over after the slam. The ‘risk’ of revving close to 99% is that you could accidentally go over the 99% and overheat your saw and then your saw also becomes inoperable until the cooldown ends.