FX Impact Power Adjuster Wheel - Never Never Adjust the Power Wheel When

Ok, got my new FX Impact and read the owners manual front to back. In the manual, there are 5 Never - Never warnings on pages 12-13. Can someone tell me about Number 1 Never - Never that says: Do Not Adjust The Power Wheel When the Gun is Cocked. What causes the damage? and What parts are Damaged? Needless to say I have not done this but I have read the entire manual first and Im curious. I don't think ER has done a video about this issue and I have not seen any others on UTube.
 
AirSupply hit it right on the head. However, you can adjust the power wheel down and nothing will happen. I don't suggest doing it, but it doesn't hurt anything. If you need to adjust the wheel. Just open the hammer back up, remove the mag, decock the hammer and make the adjustment. Then take your shot. When you go to take the shot after that one, just put back in the mag.
 
I bought a used Impact that the wheel was adjusted after being cocked. The adjuster screw that you can fine tune rests right against the cam on the wheel. It is steel, the wheel is aluminum. The end of the screw carves a groove between the settings. Essentially the numbered side of the wheel is ruined on mine. The lettered side is still usable. I cussed the previous owner for being ignorant, but guess what I always catch myself trying to do when I am running it over the chrony? It is so easy to forget that you were going to change settings before the next shot, only to rack that side lever back and then remember to change settings. 
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