It's welding all right. This old Lincoln is only good for welding since it's too early to even have the 115 v (dc) outlet which is good for tools that have brushes. A Lincoln SA200 (or SA250, SA300, SA350, etc.) is known as a pipeline welder and is about as good a stick welder as you can get, smooth as butter. From time to time I need to build or fix fences, pens, cattleguards, barns, etc. and I seem to put that off until I do a whole bunch at once, hence the several days of hard running on the machine and then back to sitting under a tree for 10 or
12 months (the machine, not me!). By the way, I bought a Miller suitcase wire feeder a couple of years ago, and it runs great off the old Lincoln. No auxiliary power needed or anything, just attach the Lincoln leads and go - apparently the Miller has a voltage sensor and hooks up fine to the constant voltage dc power source to run the wire feeder. Just need to use flux cored wire outdoors because of the wind. Speaking of crud in the gas tank, I think you're right, the glass fuel bowl fills up with rust flakes and that stops up the filter, etc. etc. A few years ago, I opened up the steel gas tank (it's built like a clam shell), cleaned it all out with a wire brush, and then put it back together, the rust came right back. Do you know of a product that I could line the inside of the steel gas tank to prevent it from rusting again? I think water condenses in the tank over time. I didn't know about the fuel pump blockoff; it's a gravity feed system, but I know that Continental Red Seal engine was used to drive a jillion different machines, and maybe still is FAIK.
You think it's possible that a single 12 v battery might be sufficient to turn the 40 v generator?