Home Guy wrote:
Tony Hwang wrote:

Hi,
Rule of thumb, you don't replace cap. with lesser value. If same one
is not available, use one with larger value. Even tho meter shows it
OK, under voltage in circuit it can go bad.

But why could I get the motor to start by bumping the machine?

Are there centrifugal contacts in the motor?

Or was the bump enough to get the spindle turning?

Hi,
You're doing the job of the cap.(shifting(leading) current phase)
Motor winding is inductive, with cap. you counter the inductance.
That cap. is called PSC(Phase shift capacitor). Most new appliance,
even garage door opener, vacuum cleaner, furnace blower, nowadays use
smaller more powerful DC motors. DC motor's efficiency is higher than
AC motor using PSC. Also Diesel electric locomotive propulsion is
by DC motor. Diesel engine drives generator, which in turn it drives
DC motor. That is why it is called Diesel electric locomotive.