Please Check this first though....
Sometimes it's simply the fact that the motor is starved for current or amperage.  Amperage requirements on the motor of the pump are typically on the nameplate of the motor and may be listed as FLA which stands for "full load amps" should be checked against amperage supplied to the unit by the electrical service box (check the breaker).  Many times we have seen a situation where the pump won't start or the motor is clicking and it is simply, there is not enough amperage being supplied to the pump.  Try plugging the pump into an outlet where you know the amperage is right and plentiful (20amp).  If it works then you need to up size the breaker in the breaker box or take some things off that line so that the pump gets enough current to run.  Make sure you have a decent extension cord engaged if you are using one.  Too "lightweight" an extension cord can cause the same problem, not usually, but sometimes.  We ask you to isolate the pump to a good circuit...... as if you have a circuit with a freezer hanging off it, and a PC over here and lah de dah de dah then we are not really giving it a chance.  Please arrange a fully amped power source to test the pump before we go shipping pumps around the country.  Again we have already been there, done that and freight today is expensive.

If there are still problems with the pump the chances are good the motor is not functioning correctly.  Many of the fractional motors now come from other countries.  They are not made in the USA and we have seen widely varying quality levels in this area.  We see a lot of motors at the factory and we do see a fair amount of junk.  ( Must be all that ISO 9000 stuff, since all our vendors in this area are rated as such. )

We just got in 10 motors and 1 failed, 30 motors and 1 DOA.  That kind of stuff is not uncommon here.  We sincerely try and we test them first out of the box, then hooked up to the end pump but still they get away from us.  We apologize we have tried all we reasonably can do.