Always a mystery ripping things off the motor waiting to discover where a water line blockage may appear. This time was no different. Two blades broke off the impeller. One actually lodged in the upstream ( raw water) supply tube inside the bronze housing. I thought it was all fixed. No - that would just be too easy.
Had this happen once before, so I stuck a flat blade screw driver into the metal "T" pipe that goes into the block from the water pump. You need a long screwdriver to get all the way in to the cylinder wall - most are too short. A phillips screwdriver would work too. I found a reamer in my workshop that is the exact fit to remove scale and gunk that builds up in that supply tube. It is 5/32 ID. A long drill bit would probably work too.
This is the second time I have had to clear out a blockage on that intake port.
Will test drive it this week.