BELT SLAP!!! Anyone else with this problem?

Mahalo 67! You may be on to something with the harmonic.

All the pulleys are clean no nicks or bends. One thing I didn't mention is i can see the pulley on the pump actually move in and out when the RPM's increase. like the pump is physically moving back and forth (front to back) but not the brackets moving just the pump. I'm replacing the pump anyways...so I'll see if that was the culprit.

strange though...