I need your help on adjusting water pressure at the pump.
the pump is a myers with a voltage regulated presure switch.
there is a big screw and a little screw. Should'nt this pump
like my other one with a water presure switch cut in at 20 and of at 40?
the presure is now about 25. can you tell me which scew is the cut off and which is the cut on. or is this the place that I need to be making adjustments. thanks.

 

Carl,
To increase water pressure with a pump system, you first need to make sure that the air in the pressure tank is holding at about 30 lbs (around cut-on pressure). Check it with a tire gauge, and pump it up with a bicycle pump, or portable air tank or compressor, if necessary. If it won't hold the pressure steady in the tank, you have to replace it.
Your pressure switch reacts to water pressure, and automatically turns the pump on and off on demand.
If you're uncomfortable around exposed hot wiring, unplug or turn off the pump at the breaker.
Pressure switch adjustment:
The large spring-loaded nut adjusts your lower cut-on pressure.
The smaller one adjusts the higher cut-off pressure.
Turn the nuts down to increase either. You should be able to get better than 20-40 pressure. Try to get it up to at least 30-50, if you can.
Good Luck!