Thanks Chris
Going to start with the impellors and work down the list.
How long ago was it last serviced if you know?
By the book, you're supposed to change impellers regularly, although most people often don't. Over time, they start to dry out and then they start breaking up and then don't pump as well.
Also, if you dry start your motor that will quickly burn up an impeller even if it is new. Sometimes people think they can just click the motor over to see if it will start and they don't realize the pump needs water for lubrication, so the impeller can quickly burn up. It also can happen inadvertantly, when someone attempts to service their motor on a waterhose and it isn't hooked up properly or the water pressure isn't sufficient enough etc.
You can get a water pump rebuild service kit from your local dealer that has the impellar along with other seals needed to do a complete service.
Good luck and let us know how you make out.
Hopefully that will be the cause and you'll be good to go after that. If not, then it's one routine maintenance item done and one possible cause you can cross off your list.
-Chris