Small Engines (Lawn Mowers, etc.): carburetor trouble, engine 143, lawn mover

Question
I just installed a carburetor kit in a B&S 12 hp ovh
engine.
143 41602  Serial No. 1081D  Craftman Riding Lawn Mover, Model No. 917.249401  Serial No. 0701S70568

NO.1   When trottle is in idle position and the engine is idling, I pushed the trottle to fast position, the engine will not increase its rpms.

NO.2  If I adjust the carburetor to run fast, and put the trottle in idle position,the engine will not idle down.

No.3  If the engine is running a high rpm, the engine will slowly increase its rpms, and the govenor will open and the engine will run at a real high rpm, the govenor will then shut down, it then will repeat this process over and over.
Thanks for your help,
Very Truly yours,
Frank Rose

Answer
Did you mess with the governor arm screw when you rebuilt the carb?

Is the governor rod binding?  Are there any adjustment needles on your carb...some carbs do not have any.

Did you blow compressed air through the carb orfices when you rebuilt it?
Was there debris in the carb?
Let me know.
Eric