My 18 hp B&S model 422707 is still surging.I have cleaned the carb.and set the enrichment screw.Any ideas out there?
Jack

I hate to tell you, but sometimes it takes more than one cleaning to remove all the microscopic dirt and trash from a carb. I would clean it again. I know this is not the answer you wanted, but it may work. Also , does it have a fuel pump, I am thinking it does. Take the fuel pump apart and clean it also if so equipped.