First check if the fuel line between tank and carb is not clogged by disconnecting it from the carb and see if gas flows out of it. Then you should close the fuel shutoff valve, remove the carb from the engine, remove the bowl, float and needle (be careful to take note where every part goes, if possible take pictures you can refer to later), and spray aerosol carb cleaner into every passage, then run a small-gauge copper or aluminum wire through the main jet and nozzle to remove deposits (if some are present) and then blow air to dislodge the grime along with the cleaner but be careful not to blow out essential parts such as gaskets and valves. Gaskets that are difficult to remove will be even harder to put back so better leave them alone.
If the carb is heavily gummed you should get a gallon of carb cleaner (it comes in a container similar to a gallon of paint), drop the carb into the container and let soak for 24 hours, then blow air in the small passages before re-assembling and re-mounting the carb. Once everything's back in place open the fuel shutoff valve and you should hear fuel pouring into the carb, check for leaks. A leak at that point usually means you have forgotten to put a gasket back in place or damaged one, in which case it will need to be replaced. If the carb is old and the bowl leaks from the top you can seal the bowl with epoxy steel from the outside once you made sure it's working properly (engine may chase while there's a leak), this will stop the leak but you won't be able to service the carb in the future so you'll need to buy a new one if problems resurface.
Honda HS928 TCD - If you lived where I live you'd have one too
