That happens when you shut off the motor & the trapped fuel pressure in the pump to carb. line rises due to heat & overpowers the float valve in the carb., spills over, drops onto the butterfly, runs across its shaft & out where you describe. Has to be some clearance there for it to operate. If the shaft/base wear too much you will know it by it not being able to idle down to a normal RPM due to the air (vacuum) leaking in. Try lowering your float level a bit, that helps usually. When its really wore out as stated before you need a rebuilt one. Good luck finding one in the store thats been rebushed. May be more easy to find another old one in better shape, all you need is the base part. Some of these have sat for many years & never got worn much. I've gambled on some ebay ones for a cheap price & got lucky before. Doug
