Wire Feed Tension
by Rod Hancock (Welding Rod)
(Vancouver Island, Canada)
The best way to check your wire feed tension is to hold your hand about an inch from the nozzle.
Trigger the gun; if the wire stops while the gun is operating, tighten the tension slowly until the wire continues to feed and crumples up in your hand.
This would be my experience with aluminum; steel won't fold as easily so hold your hand 2-3" away for steel.
Hope I don't have to tell you to wear a welding glove while doing this!