My buddy just recently bought the Honda 630 8gpm with EFI (I believe) and it kept shutting off. Would run fine all day some days and some days it would shut off after an hour, or every few minutes. Not sure what the exact issue was. He took it back for a 690 and hasn’t had a problem since 🤷🏻 side note, he initially tried buying a igx 800 EFI from Barry and Barry said he quit selling them due to too many people having problems with them. Hope you figure it out brother!