Plasma Cutter Torch Tubing ??

My first little mig was a Hobart, used the crap out of that machine, welded great.
I gave it to my Dad, it still worked but all it needed was a new liner.
I replaced it with a new Miller auto set. I think the Hobart was smoother.
My brother bought a new Lincoln 220v , that thing was terrible and I`m a Lincoln man, when it comes to engine drives.
Way back before that Hobart I had a Lincoln about the same as it. It welded great. I had a body shop friend back in Mo. that had a Hobart same model as mine, he said his never welded worth squat till he reversed the polarity to the wrong way! I have tried mine both ways. But I bet my liner needs replacing again and the wire roller.