Small Engines (Lawn Mowers, etc.): snowblower engine problem, brass nut, float bowl

Question
my snowblower has a techumsah engine. i can get it to start and run, but when i try to remove the choke all the way it stalls. it only runs with the choke in the 1/2 position. it works that way but not at full power. the carb. was professionaly rebuilt last year and had no troubles. can you help

Answer
Is the fuel fresh?  Less than 30 days old?
Do you have a float style carburetor?  You can tell by looking at the carburetor;  the float bowl will be located on the bottom of the carb, will be round and held in place with a brass nut.

Let me know.
Eric