rj,
What size generator do you have running the pressure washer?.
Water-blasters (as they are called here) have a huge start up current, hence the large number of capacitors.
But 3 of them?, in a Cap Start, Cap Run motor, there should be 2 capacitors.
All these capacitors do, is improve the power factor of the start and run currents and to a certain extent, lessen the curretnt load through the centrifugal switch on these motors. [Linked Image]