Actually, my Big 40 has a smoking rheostat. It does not weld very smooth either. Generates 115 VAC fine. I believe bad diodes are the culprit. I was confirmed that by a few people I talked to about it as well. Someone replaced one, as well as some other stuff inside long before I bought it. It may have not been done right, hence the rough arc & smoking rheostat. Going to tear it apart & put some time into it when I actually get time. Who knows what else I'll run into when I do. I only paid $750 for it & her 162 connie runs like a raped ape. Heck, the motor's got to be worth that. Good luck with yours NMWELDING. Weldersales has more parts for these than you could ever imagine, so if you need anything for it, he would be one to call. Kaye @ Bill's is awesome & could have parts as well. S.W.