: You don't say what product the sump pump is discharging, its horsepower, and at what pressure, nor do you say what condition the pipe wall is in, or its material. Using a sump pump of very good quality like a Teel residential sump pump with a 1 1/2 inch discharge reduced to 1 1/4 discharge will work fine. Teel shaded pole motors have automatic overload protection and are oil filled for continuous bearing protection.
: : My sump discharge line is 1.5", with a 10' head and a 20' fun. Can I use a sump pump with a smaller discharge, say 1.25"? Is this putting extra load on the pump, since it has to shove the water through a larger area than designed for?