I'm not sure I understand what you are trying to say. When you said that with the motor off water flows freely from the barb on the pump what do you mean? If the jet pump isn't spinning it can't be flowing water. Or are you saying that you unhooked the supply line from the jet pump and hooked up a hose to it and it flowed through fine, but when it is hooked up to the pump and running in the water it isn't moving water? If that is the case pull the bowl off the pump and have a look around, something is clogging it up in there blocking off the supply outlet.