I have a water pump, it works fine. Motor is rated for 115/230 and draws 9.6 or 4.8 full-load amps depending on voltage. Its cord has a plug that appears to be vintage NEMA 10-20, but I'm not certain as I've never seen one before. The receptacle is on its own 30-amp dual-pole breaker, and I verified that the wiring is two hots and a ground.
I want to run this pump from my generator, which is an older 5000 watt Troy-Bilt with standard 240v L14-30 and 120v 5-15/20 receptacles.
The problem: I can't find any adapters for 10-20 plugs anywhere. Is this just because they're obsolete? Or because they're ungrounded and super-dangerous?
Main question: Should I bother making a custom adapter cord for this setup or just upgrade the plug and receptacle to something newer? Is one option obviously better/safer/easier?
Pump motor is a 1986 Dayton 5K658B 3/4HP 115/230 3450 rpm. I found this tech sheet but I'm not 100% sure it's the same model.
Based on the discussion in the comments, this whole situation is more complex and sketchy than I had anticipated. I have other electrical work I need done so I'm going to add this plug/receptacle to the list and seek professional help.