C10MixMaster, @bucket,
I'm a welder to and I'm not going to bother to explain how much experience I have unless you want me to go into one of my loooog ass writings, okay.
@wanderinthru is partially correct. Usually the motor doesn't go out or have the problems
@bucket is talking about, and I know what he's talking about. It's like the wire is surging. There are three or four things that can cause problems and here is what you need to pay attention to. 1. Make sure your drive wheels are kept clean. They can pick up little bits of metal from driving the wire into the liner. If they are allowed to build up on the drive wheels it can cause the wire to slip, and dirt or anything else. 2. There isn't any good way to keep the liner clean. You might remove the wire and maybe blow it out with compressed air, but otherwise just make sure your wire spool is kept clean. Don't leave your welder on the floor where dust and dirt can blow into it or get in somehow. 3. Do invest in a can of the spray that keeps the tip and the cup clean. And buy a bunch of tips. They're cheap and can keep the weld going. Get the proper tools to service the tip and also keeping the cup cleaned out as well. Get the tool to scrap out the cup so the gas comes out smoothly and isn't being partially blocked or interrupted by spatter or that smoky stuff especially from flux cored wires.
If you can afford it
@waterpirate, get yourself the regulators for Co2 and Argon gas so you don't have to use flux cored wires. They are filthy and put all kinds of contamination into the weld. They aren't good for anything that doesn't involve hours of clean up, besides all the scratches and dings from banging all the bb's off the area. You may not need the Argon but at least Co2. If your doing plate and doesn't require so much cleaning flux core is great, you can run a lot of current through those wires. When you gain experience you can introduce Oxygen and Argon and then you'd see some beautiful welds from wire. Also if you can afford it get a welder that has a voltage control so you can get the flattening you need and the penetration you want.