MIG welding problem finally solved after years

The manual will tell this info, guess you bought it used, without manual.
It may even say on the info sheet, on the backside of cover door?
My brother has a lincoln 220 machine that he says it just won`t weld right, I`ve used it myself and just does`nt seem to weld smooth. Later,
I recalled the polarity deal, asked if that was correct. He said it was and still welds funky?
I bet your a happy camper now:-D