Just went through the air tools. All of them were checked and oiled including the one that no longer has the INOP tape on it. All of them are working with the exception of the grizzly air nibbler (it need a new tooth).
If it doesn’t seem like the die grinders are spinning fast enough, there is an adjustment screw on the opposite side of the trigger that can be turned to either allow more or less air through to change the speed of the grinder.
If something else doesn’t seem to work or you’re not sure how to use the tool, let me know.