Last year I bought 3 motors from a junkyward, and one of them was a 1/4 hp, 4 pole single-phase induction motor made by WEG for an Electrolux washing machine.
Or at least it was supposed to be, cause most were disassembled and thrown in a pit, so I had to go around matching rotors and stators.
One was already complete, another was the correct match and this one I'm talking about I thought to be correct, turns out it wasn't.
Firstly the rotor is about 7 mm shorter than the stator (the stator is taller). The bearings aren't fully sitting in their sockets either.
But, most notably, the airgap is absurdly small. The rotor isn't scraping the stator by a miracle, cause the airgap is literally invisible. If I put the motor against a white screen or against the Sun I can't see light passing by any angle.
I've never seen such a small airgap, most are pretty visible and specially if you put against a light source.
I've run it by some minutes to see if thermal expansion would cause it to scrape, and it didn't, but it also heat a hell lot more than it was supposed. it reached 80 ºC in about 6 minutes, and most notably the rotor heated too much.
Could the reduced gap be increasing the rotor current?
The overall operating current seems to be close to normal from my measures.
It could also be that the rotor properties aren't the same of the original design, but from pictures it seem to be mostly identical and I counted the same amount of aluminum bars.