Let's do clear this all up. The slot was cut to hold the stud whilst tightening the nut. Period, end of story. Rotating that stud in either direction either increases or decreases tension on the cam chain. The tensioner is an automatic tensioner. The problem is that when you loosen the nut, the tension automatically sets, but when you go to tighten the nut, the moment the washer in front of the nut comes in contact with the o ring, it tents to rotate the stud with the entire mechanism altering the tension. That's why you have to let the tensioner set itself, then hold the stud with a flat head while tightening the nut.
What causes most damage to the teeth are both lash over time, and people forcing it tighter to try and eliminate noise from the chain, so they hold the stud in the tensioning direction while tightening the nut. The entire mechanism just wasn't designed to work that way, with more chain tension forced into it. You'd be surprised how many people thought they were doing no harm by doing this. that ALSO puts way more stress on the upper and lower ends of the slipper which causes it to crack from the front backward. 😳
