I have honda fg 110 a mini tiller it starts fine
I have a similar problem.
The first time it was cause by the ethanol in the gasoline. It deteriorated the carberater rubber membrane so that it had a crack in it. The carberater would run lean. Take off the primer bulb and there is a plastic cover that goes over the rubber membrane. Remove that cover, and check the membrane. If this has a crack, you can order another from a honda dealer. It is about 14 dollars. After that just use ethanol free gas. Search the internet for a local source.
The second problem I had developed a little later. The engine would start, but if I gave it full throttle, it would quit. It got worse and worse till it would run at all. I noticed when I loosened the Gas cap, then the engine would run. And when I loosed the cap, I heard a whoosh, like air being sucked in.
So I figured the cap wasn't breathing like it should, which cause a suction in the gas tank. So I took a diaper pin and went through the holes on the inside of the cap, and through the little rubber plug in the center of the inside of the cap, several times. This allowed the cap to breath. Now it runs great.
on May 18, 2014