Small Engines (Lawn Mowers, etc.): MTA runs rich, mtd mower, carburetor


Question
This is a MTD mower which I am sure you knew.  Anyway I removed the carb one more time, checked the new gasket for tears, reinstalled it so I was sure the little flaps that control the gas flow to the jet covered their respective holes.  I then started it and after it bagan serging I blocked the air flow to the carb until the engine almost died 3-4 times and it stopped serging and ran perfectly at high speed and idle.  Problem solved but why?  Was it air-locked?
-------------------------------------------
The text above is a follow-up to ...

-----Question-----
Hi again John,
This unit was dead when i got it.  Cleaned the no adjustment plastic carb up well with carb cleaner and compressed air.  It started but ran very rich and serged. With new carb gasket it ran much better but still rich and serging with new air cleaner element.  What next?
-----Answer-----
 Hello Steve:

 With the Plastic Carburetors, if a Clean and Rebuild Doesn't Correct the Problem, then a New Carburetor is Next. Hope this helps. I am here if you Require more Assistance. Let me know what Happens, Please. thanks.

 Good Luck

 Respectfully

 John

Answer
 Hello Steve:

 The Carburetor had a Blockage and by Choking the Carburetor you Pulled the Blockage Through the Jet and Cleared it from the Carburetor. Carburetors Work with Minute Particales of Gas and I'm Talking Very, Very Small Particals. It Doesn't take Much to Block the Jets. I'm Glad it is Working Fine now. May All your Mechanical Problems be SMALL ONES and May the All Mighty Bless You and Yours. Thanks for the E-Mail Update. Till Next Time.

 Best Wishes and Good Luck

 Respectfully

 John