Remove the air cleaner and the carburetor. Replace the gas and all the fuel lines with new parts.
Get a carb rebuild kit from a local shop or buy online. Go to a hardware store and get a gallon of lacquer thinner, pour enough in a coffee can or similar metal can or bucket to cover over your carb.
Remove all screws and jets from the carb and dunk everything in the lacquer thinner for about 24 hours.
While everything is apart, be sure to check the tightness and security of the bolts on the engine. A lot of times the nuts or bolts that hold the 'jug' on the crank case come loose allowing too much air in the cylinder causing too lean a fuel/air mixture and hence having to run it on choke all the time.
Use new parts to rebuild the carb. Reinstall carb and fuel lines and air cleaner. Tighten all screws and nuts tightly. Add new gas and it should be good to go.
Regards,
Frank.
PS, search Youtube for your specific type of equipment and chances are you will see a video tutorial on just exactly how to fix the exact problem you are having specific to exactly the type of equipment you did not specify in your question.