The capacitor in this discussion is a Run capacitor, not a start capacitor.
Your progression to this point has been backwards.

When the motor hums instead of starting, it's not because the value needs to
be 8.645789uF, it's because the motor is not wired properly.

You need a qualified, experienced person to take care of the installation.

--
Cheers,
WB
..............


"Deodiaus" wrote in message
...
Actually, where do I find a site with the physics of starter windings
on motors explained. 30 years ago, I had someone explain this to me
in a class, but I have forgotten it all.
Any good descriptive web sites??

BTW, does anyone know of cheaper motors on the web?
https://www.plumbersstock.com/produc...rtNumber=12476
The above site lists some substitute motors, but some just hang my
browser .