My 15,000 watt generator has very little hours,
Its most likely the float, the fact that turning the fuel shutoff on full makes it die tells me its flooding out, and the fuel shutoff partially turned off is just regulating the fuel flow in place of the float. Time to take apart the carb and give it a good clean, if its running well otherwise with the shutoff partially off then its most likely just a sticking or bad float or float valve. You might be able to get away with taking just the bowl off the carb, pulling the float off by removing its pivot pin and cleaning the needle valve and use a q-tip soaked in some carb cleaner and clean up in where the needle valve goes, because it could be gunk built up on the end of the needle valve or up in the needle valve seat causing fuel to keep flowing past it. Also while your cleaning it put the float in a small container of gas for a while and make sure it doesnt sink! If it does it has a hole, but you should also notice the float has fuel in it when you shake it. Most newer engines now have plastic floats, and they don't usually spring a leak like the older brass/copper ones, but its still worth checking.
Long story short, yes, you most likely have a float/needle valve issue.
on Jan 11, 2018