Small Engines (Lawn Mowers, etc.): Cub Cadet 173cc runs badly, cub cadet, carburetor

Question
Model 12A-18MC056 runs badly with the choke off (pushed in).  When starting and the choke pulled out, the mower runs OK.  When the choke is turned off - pushed in - it begins to pulsate badly and runs very rough with black smoke coming from the exhaust. It seems like it's flooding itself with the choke off. Thanks for taking my concern.

Answer
Have you tried cleaning the carburetor?  We have had some trouble with this engine, the carburetor.  Sometimes cleaning fixes the problem  but sometimes we have to replace the carburetor with a new one.

Try cleaning first.  Remove carb, dis-assemble and use compressed air from an air compressor to blow through all the carb orifices to clean them.

Let me know if cleaning fixes the problem.
Eric