Engine will not idle after starting
not knowing what model you have makes it almost impossible to suggest a repair, however, your problem indicates a fuel supply problem, if your unit has been in storage, or not used for a while,and was shut down with fuel in the tank and carburetor, it is likely that you have fuel that has stratified, and turned into a varnish inside, which will require a dis assembly and thorough cleaning before it will idle, if it has been in use, it might still need complete carb clean, also check you fuel filter, usually it is something that is just being overlooked, spark plug???? spark plug wire? ignition coil air gap??