For those who this may help, the Ohio builder of the S1 (Snakebite) put our a service bulletin that mentioned that some of the fuel wiring connections could work loose and cause resistance at the pump, one of the big indicators was that the pump sounded louder. I have S1 #13 and had this looked at when I started to have this problem. Also had a chunk of silicone in the filter just below the fuel cell. SW