Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Put a teaspoon of fuel into the spark plug hole, re-install the spark plug and see if it will start for a few seconds.
If it does, the spark is good, and the fuel is not getting to the cylinder. The carburetor is not passing fuel. Remove the float bowl on the carburetor and see if fuel is flowing to the bowl from the tank,
The fuel may not be going through the main jet, which is the bowl bolt and the passage up the middle , the bowl bolt goes into. Lots of small holes at need t e open. Also the needle valve, if all metal , will have an upper rubber seat that can swell and not let enough fuel into the bowl. Common caused by ethanol in the fuel.
I doubt you got all the dirt out of the main jet and the bowl bolt. Both have tiny holes in them that need to be perfectly clean and open. I would remove the bowl again, and check the holes in the bowl bolt, use a bread tie wire to clean the holes. and use spray carburetor cleaner up the main jet, the center post of the carburetor. Your almost there, still starving for fuel.
The engine is not getting enough fuel. that is why adding choke helps keep it running. Is the needle valve an all metal needle or does it have a neoprene tip? If all metal, it has a rubber seat in the upper needle passage. This rubber seat can swell and not let enough fuel flow to the bowl. Repair would be to replace the needle and seat.
The all metal tip has the upper seat, which the ethanol from the fuel affects, and it swells and plugs the fuel passage. It can completely close it, or just restrict it.