Small Engines (Lawn Mowers, etc.): Engine kills when choke is open, fuel tank cap, plate moves

Question
My rototiller has a 15 yr old Tecumseh H30. New plug & air filter, clean gas.
clean carb... at least I tried cleaning it out. It starts right up with choke closed
but after sufficent warm-up it kills when I start to open the choke. Choke
plate moves free and easy. Exhaust is pretty clear. The carb has 3 screws... 1)
under the float bowl 2) idle speed (I think) and 3) idle mixture (I think). Do
you think the problem is with those settings or something else? Any
troubleshooting tips would be great.

Answer
Jeff
Possible causes:

Fuel tank is empty or shutoff valve is closed, or fuel line or fuel tank cap vent is clogged.
Carburetor is overchoked.
Carburetor is improperly adjusted or needs service.
Check for these problems usally when you open the choke it is not getting enough fuel.