Buzzbox missing its buzz

[sardine]

Acquired an old barn find 140 amp basic air cooled moving core transformer stick welder, the OCV drops to zero when I strike an ark, there is a weedy little arc not enough to light up a 2.5 with the machine on full power, anyone know what's wrong with it ?

 

[frank horton]

pop the cover off and look for loose or dirty terms.....
they hardly ever go wrong......unless seriously overheated....

 

[gaz1]

direct to earth can cause that as ive seen it with the clarke mig welding machine

same exact issue

 

[Barking Mat]

Where I started, good old buzz boxes.