Gonna offer a follow up comment then another possibility that may have been missed.
Someone reffered to a induction repulsion motor. I have always reffered to them as repulsion induction. ie Repulsion start Induction run. These were the best thing for hard starting loads. They were also high maintenance since they had brushes that needed to be replaced. They also haven't been made for thirty years or so. What you likely have is a split phase motor which are the worst for starting loads I didn't think these were made as big as 1 horse though. A capacitor start motor should be adequate.
Another suggestion, What ratio is set up in the drive. You said the motor is 1750 (no load of 1800). Should have at least a 3 to 1 ratio. No point in running a auger faster than 600 rpm as anything faster is just spinning your wheels. At least that is what my prof taught me at ISU.