2PSI doesn't sound like
much water pressure at 4000 rpms. What is the spec on it?


The best I can tell it is 16 lbs.
I had it out tonight and I start out at about 4.5 psi until the thermostat
opens and then I am back to 2 or so. I really think the water supply tube or
the manifold must be plugged. with limited flow the pump pressure will max out
at a pretty low RPM (water starts blowing by the impeller), then more RPM won't
do much for the pressure.
I am really thinking if I get back in there myself I will make a snake from a
screen door spring and snake out that pipe.