FWIW the drive pulley /countershaft gearing is way off; a 2"-and-a-bit-ish motor pulley should be driving an 8 or 9" pulley on the countershaft, so at the moment the motor is having to work extra hard (like trying to pull away in top in a car).
It will help a lot if you put the lathe spindle drive onto the 'slowest speed' pair.
The motor might also be clapped, or even a bit cooked from this treatment, but fixing the gearing before further testing will at least clear the field for an unambiguous result.
Edited By DiogenesII on 01/04/2023 12:21:24