My middle carb has an enrichment valve on it and I would like to know how it works. I have the carb off the motor and the bowl off the carb. How does the middle carb bowl get fuel. I try to blow through the inlet and can get pressure to go anywhere. Can the enrichment valve be the problem? I have checked the valve itself and it extends as it should but I have no clue as to how the middle bowl will get its fuel. Everything inside the enrichment valve looks OK. The diaphrams have no holes and the little check valves seem to be alright too. Thanks for any help. Billy