Ok, I know how to mig weld, I know what cfh to run, what voltage, and wire speed for diff types of metal and metal thickness but I am encountering a MAJOR problem that for the life of me I can't figure out.

Ok so when I weld instead of the "bacon & eggs" sound it makes a "hissing" sound like a snake. It burns through everything and doesn't flow well.

It's a Millermatic 200, an older one, like 10-15 years or so. It usually works good, but I don't know what could've gone wrong.

Does anyone have any Ideas? A professional welders experience and knowledge would be greatly appreciated.

thanks,

Roger