Since these are presumed to be DC motors, they'll take infinitely variable voltage up to their limit, at which they may also limit out on amperage...and that's the problem. If they are being required to do work at the same time, they'll begin to take up amperage commensurate with voltage, and they'll begin to get warmer, and warmer...and...
I like the last suggestion; if there's a name and model, do a www search and see if anything pops up, or simply contact the manufacturer.
Some years ago I Googled the name and motor number and found the specs.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
if you have a variable power supply, or an old transformer ... you can start at maybe couple of volts and slowly work your way up .
you can also probably look them up on the 'net to find out voltage range ...
I have several can motors that I found in a plastic box in my garage, but I don't know their voltage. Is there a safe and simple way to determine what voltage these motors are without frying them or myself? If so, can it be done with an analog multimeter, as I own one? Two of them are made by Mabuchi, but none have any voltage ratings on them.
Thank you in advance for any and all tips.