Miller Big Blue 251D Problems

[Pulpwood]

Serial # KG122705.
It will only weld at highest setting with fine tune wide open as well. And also 120 V receptacles are not producing enough current to run a small grinder.
Help would be greatly appreciated.

[cruizer]

Not going to high idle?

[Pulpwood]

No. It doesn't really have idle. 1850rpm constant with no load. It's an older Deutz engine driven.