...instead of a fuel pump. And is it pressurized just by the vapor pressure of the gasoline? (I have a 12" chainsaw like that)
Kubota zero-turn mower. My brother said he forgot to put the fuel cap on it a few months ago and ran it for just a few minutes like that and the engine started cutting-out. He figured out the missing cap and put it back on but it died. Actually, it would have died when he got off the seat and I guess it wouldn't start again. He pushed it into the garage and there it sat. Now I'm visiting
Once before it wouldn't run and the dealer said the fuel line was clogged up with grass and *expletive deleted*it and they replaced it and charged quite a bit for that; but I might have heard the story wrong. Anyway, I pulled off off the line between the tank and the fuel filter and blew thru it. It was fine and I put it back on. The clear fuel filter was over half full. Engine still wouldn't start. Wouldn't even try to start.
I bought some starting fluid and sprayed a little in the air filter housing. It started right up and ran for half a second and died. Okay, I know it's a fuel problem. Check the fuel filter in case the outlet of the gas tank is clogged up. Fuel filter is full. Another day or two passes while I work on other things.
Today I looked it over, and I couldn't find anything identifiable as a carburetor, but I didn't see anything that looked like a fuel pump either and the gas line runs uphill. I made sure the gas cap was tight. (it was) I took the air filter off and sprayed it really good with starting fluid. Put it all back together and crossed my fingers and tried starting it. It started right up. Ran a little rough for a few seconds but then leveled out. I revved it up and it kept running. Put it in gear and it did okay. Drove it around a bit, then engaged the blades. Seemed alright, so I mowed for about 10 minutes with it and shut it off. In about an hour I'll see if it still will start and run, and if it does call it good.
So what really happened? Pressurized fuel tank is all I can think of. I also see an evaporative canister like the pollution control stuff on a car, with a fuel line going to it. Maybe it uses the PCV valve or a little air pump to pressurize the gas tank, and only relies on the vapor pressure to get it started when it hasn't been run in a while? That's the best theory I have. I don't have a service manual for it.