I posted a response to a 300d question a while back, about how it didn't light up well. I asked a welding machine tech for miller, worked at the factory as troubleshooter and teaches welding tech, super smart dude, especially about welding machines. He said that one of the biggest problem with engine driven welders and some non inverter electric welding machines is that people, including welding salesmen and reps don't realize is that they need to "run in" the machine on a load bank. I heard some talk about using a long length of wire fence or old bed spring mattress from some seasoned welders of which i asked the tech his opinion, the tech said thats better than nothing but having the welder properly "run in
by a weld tech saves a lot of money in the long run. Without it all sorts of things can and will go wrong. Like the motor will not have any resistance and will not seat the bearings or rings correctly, never mind a whole host of issues that can arise from the electrical system not being addressed correctly.
     Perhaps one of you who has better knowledge than I can elaborate on the topic in the hopes of saving many of our brothers and sisters a whole whack of money and trouble that is caused by this lack of information. Man o man where would we be without all the technicians and others that are working behind the scenes to make it so we can make and keep a stable arc.
Thanks
darren