Pulley size
Hi mdmade78,
Congratulations, it is a really beautiful compressor, I have seen the specs in the manual:
http://powerspecialtiespumps.com/images/manuals/Quincy-QR25-Model325.pdf
It is a dual stage compressor, up to 200 PSI continuous duty with a recommended speed from 400 to 900 RPM. If we select an intermediate speed of 750 RPM, we need a motor to compressor speed relation of:
1725 RPM / 750 RPM = 2.3
In accordance with the specs, the compressor pulley is 14" in diameter, so the motor pulley diameter must be :
14" / 2.3 = 6"
With this diameter relation (2.3), every 2.3 motor turns, the compressor will make one turn, and in one minute 750 revs.
Enjoy your compressor!