I've been rebuilding small engine carbs since the '90s, but I finally came across one that beat me and thought I'd share. It's a Honda EG2500 generator that I picked up cheap non-running and with a crankcase full of gasoline. I pulled the carb and it didn't look bad inside, some sludge in the bowl but the main jet and emulsion tube were clean. I removed the idle needle, float & needle valve, etc...sprayed it out w/ carb cleaner, blew out all the passages with compressed air, reassembled with a Honda gasket/seal kit and new needle valve. Inlet valve seat is plastic, pressed into the carb body, not replaceable. I didn't see any cracks in the plastic but it's possible there was a deformity or crack in there.
Reassembled the carb, flushed out the crankcase with hot motor oil from my truck's oil change that day, refilled with my usual Shell Rotella T5 10W-30, and it fired right up. Adjusted the governor to show 59.8-60.2Hz at 1700 Watt load, nice clean power and load-tested for 2 hours. The next morning I tried to restart it...starter cord stopped cold. Pulled the spark plug, spun it over and raw gas shot out.
Pulled the carb bowl in place, verified gas flowed when the float was down and stopped when the float was up parallel to the carb body. WTH?? Changed the oil again (smelled like gas) and re-tested...ran perfectly for another 30min load test. I repeated the sit-overnight test and same result. Only if I shut off the manual fuel inlet valve did the thing stay dry.
I bought a replacement carb on EBay, popped it on and re-tested the engine. Put it away overnight w/ the manual fuel valve open, next morning no problem. That afternoon, no problem. This is a first...I'll disassemble the factory carb some day and examine the inlet seat more closely, it's just annoying.
Reassembled the carb, flushed out the crankcase with hot motor oil from my truck's oil change that day, refilled with my usual Shell Rotella T5 10W-30, and it fired right up. Adjusted the governor to show 59.8-60.2Hz at 1700 Watt load, nice clean power and load-tested for 2 hours. The next morning I tried to restart it...starter cord stopped cold. Pulled the spark plug, spun it over and raw gas shot out.
Pulled the carb bowl in place, verified gas flowed when the float was down and stopped when the float was up parallel to the carb body. WTH?? Changed the oil again (smelled like gas) and re-tested...ran perfectly for another 30min load test. I repeated the sit-overnight test and same result. Only if I shut off the manual fuel inlet valve did the thing stay dry.
I bought a replacement carb on EBay, popped it on and re-tested the engine. Put it away overnight w/ the manual fuel valve open, next morning no problem. That afternoon, no problem. This is a first...I'll disassemble the factory carb some day and examine the inlet seat more closely, it's just annoying.