Join Date: Apr 2012
Location: Cairns, Australia.
I bought a generator that had a similar problem, it was cheap and almost brand new but would only run properly with almost full choke. Without choke it constantly surged. I must have had that carb ( engine is a Honda GX270 clone) apart so many times I could do it in the dark and always it was the same. I too was ready to throw the thing down the hill, I cursed the smarmy mongrel that sold it to me, and his sisters and his mother and his neighbors....his neighbors mother....
I finally ordered a new carb online, it looked the same but didn't quite fit because of the air filter arrangement. Oh well, I started swapping jets and other bits to see if things would improve-nope still surging away. According to my research, 99% of the time surging is caused by lack of fuel, and thus it was it the end. There was a little plastic plug on the side that seemed to have something to do with directing suction to an idle jet, when I swapped the only-slightly-worn looking O rings on it for the ones on the replacement carb-bingo! Instant success, the bloody thing just purred away no problem at all.
Maybe, just maybe, you have a similar problem.
Best of luck with it!