Generator for Running a Spot Welder?
The spec page you linked to for the welder shows 4KVA but that's only about 20 amps. Seems low. The thing that occurs about spot welding, is, unlike something like mig/stick, the spot generates all it's heat in a very short time, and that gets into "peak" so to speak. Meaning you probably cannot skimp on power and do good work
Even so, many generators are overstated. For example, many generators rated at "X" power or amperage won't start some motors because of the surge. Seems like a spot welder sort of fits into that category
In other words I'd want PLENTY of (over)head room for power output at the generator.