Small Engines (Lawn Mowers, etc.): Tecumseh engine speed not constant, mtd snowblower, air mixture

Question
I was given a MTD snowblower which was only used one year but was idle a few years with gas in it. It has a HSSK50 Tecumseh engine. I took the carburetor off and opened the bowl and found a lot of varnish build up there. After cleaning it out, the engine starts easily after priming and runs however the governor is constantly changing speed. With the carburetor bowl opened, I noticed that there are two tubes vertically down into the bowl. One has the needle adjustment screw in it through the bottom of the bowl. The other parallel tube has a smaller diameter and what looks like a ball bearing about 1/8" from the end. It completely blocks the tube, doesn't budge, and nothing can pass through it. I was wondering if this is causing my problem and if the ball can be loosened up some way. How is this supposed to work and how can I adjust the needle valve at the bottom of the carb and the one at the top to make the engine run smoothly. I have not been successful so far. Thanks for any help you can give.
Gerry

Answer
 Hello Gerry:

 Remove the Carburetor and Disassemble. Soak the Carburetor Overnight in Gunk Carburetor Cleaner and Then Blow Out the Passages. This will Loosen the Metering Ball. Install New Kit. The Air Mixture Screws are Set at 1 1/2 Turns Out from Seat. Then with the Engine at Full Throttle, Override the Governor by Hand and Turn the High Mixture Screw(on the Bottom of the Bowl) 1/4 Turn In Until the Engine Revs and Has Power. Then Set the Low Mixture Screw so there is No Hesitation when throttling from Low throttle to High Throttle. Then Set the Idle if Required. You can View a Breakdown/IPL of the Engine at this Addy http://www.outdoordistributors.com/ and Click the T. Then Select Tecumseh. Then Select Don't have Part Numbers. Then Enter the Model Numbers. Then Select the Model to Download. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John