Visited a friend in the mountains last weekend, and one of the projects was her backup genset. It would start and run for a minute and die. A 5 minute wait would repeat the process. It was last run 9 months ago, and had been sitting around full of 10% ethanol gas.
Step 1 was to pull the filter (clean) and open the fuel valve--good flow. Step 2 was to pull the drain screw on the carb bowl--it was full, but when it drained and I opened the fuel valve, it flowed about 2 drops a second. Step 3 was to pull the carb, take off the bowl, and check the float valve--all OK.
Step 4 was to pull the fuel line off the carb and blow through the passage
to the float valve--blocked.
Step 5 was a shot of compressed air in the float valve, and a piece of gunk about the size of a grain of rice flew out of the passage--problem solved
Step 6 was a lecture about non-ethanol gas or fuel stabilizer.
I hate ethanol fuel.