I知 refreshing the fuel pump assembly and I pulled my new walbro 521 out of the box and it sounds like a Maraca! I知 a little hesitant to put this in. I知 thinking I either got one of the super ultra rare small batch Caribbean made walbro fuel pumps, which would totally justify the maraca music I知 hearing, or I need to send this pump back. Anybody else used the Caribbean version pump?