Alright, so I drained the fuel, and out of curiosity, turned her on to let her prime...the screech was gone. I took off the tank anyway. I wiped out the inside of the tank with a clean rag, I cleaned the entire pump. The piping on the pump shows no dents or kinks, neither the pump motor, nor the fuel filter show signs of damage. The electrical connections are good. So, I put the pump back in, remount the tank, put fresh fuel in the tank. At first the sound was gone. The sound, though, eventually came back, but not nearly as loud as it was. Any thoughts?