Hello Jim, it is very likely that you would have enough power to operate a 220V mig welder with this particular welder/generator. Depending on the particuar mig welder that you are trying to operate off of this machine, the upper amp draw of many of the 250 amp migs is around 45 to 50 amps @ max welding output, this should be within the range of the output of the bobcat. One suggestion here though, set your bobcat to high idle when you are using this combination, you will avoid all sorts of headaches with weld performance from the mig and likely avoid causing damage to it from too low of a supply voltage upon start-up. Best thing to do is consider the amp draw of the mig and compare it to the output of the bobcat generator, even if it turned out that the draw from the mig was slightly more than the output capable from the bobcat it would still probably work because unless you are maxed out on the output of the mig you won't see the max amp draw from the mig. If my memory serves me correctly the bobcats can provide around 45 to 50 amps of 220V power if they aren't welding.
Wattage divided by voltage = amperage, so look for the wattage output on your friends particular bobcat and use this formula to determine the amperage that it will supply. Then compare this with the draw from the particular mig welder that you plan on running with it. There are a few other factors with this formula and how it applies, but it should get you in the ballpark. Best regards, aevald