The inlet screen on a point can accumulate enough sand and silt to block the inflow of water. Unclogging it is done by forcing water back down the well point, then pumping in the normal fashion. It can take several repetitions to get the particles moved out of the way of the inflowing water. I use a fine mesh strainer on my own well point installations, and can see when I no longer am bringing up particles in the water.
As for the K-Rain controller, I can't help, except to suggest looking for an Intermatic or similar, like Paragon or Tork. I'm assuming the clock is turning the pump on and off.
http://intermatic.net/Default.asp?action=prod&pid=9121&sid=233&cid=51&did=5