Dependant on the motor!
If the motor has a largish cylinder fitted to the side of it with a single nut(about 2.5 inches long with a plastic cap with 2 wires going into it), then this may be the faulty part.
It basically starts the motor by providing a big surge to get the motor turning.
There are different types. On the side of it will be a microfarad rating. (looks like a funny shaped 'u' with a capital F next to it (uF). This has a numer in front of it eg: 8 uF). You will need to source the same rating.
Unplug the machine and wait for a while to allow for any residual voltage to disapate (you don't want to touch the business end of of a charged capacitor!!).
Make a note of and change these wires to the new one and bolt it into position.
B. Beale, December 2009