Small Engines (Lawn Mowers, etc.): Tecumseh will not idle, carburetor body, stop screw

Question
I have a 5 HP Snapper show blower with Tecumseh model HS50-63266H SER 81593. I bought it used and it has run well for the past 4 years. At the end of last winter, it was running poorly but I have not tried to fix it until now. The symptom is the the engine will not run much lower than full power. If you move the throttle to about 1/2, the engine will cycle. It appears it will nearly stall than the governor pushes the butterfly open. If I go much lower, it just stalls. I removed the carburetor, removed the two jets, pulled the bowl, and pulled the float off. I blew all the passages out with Gumout followed by compressed air. I saw some dirt come out but not much. I reinstalled everything, backed out the main jet to 2 turns, and the idle jet out 1 turn from bottomed out. Adjusted the main jet at full speed to get it pretty smooth. No difference in the part power problem. I even screwed the butterfly stop screw far enough in so it would keep running and made multiple adjustments to the idle jet and then would back out the stop screw but it would again stall well before getting anywhere near idle. No setting of the idle jet worked. As the engine speed was dropping, it would only take 1/8 of a turn of the and suddenly the engine would stall. I pulled the carburetor again and repeated the cleaning. I noticed there are two small holes downstream of the butterfly and Gumout was coming out of them when I blew in the idle jet. I assume this is what supplies the idle fuel. Thank you for any help you might give.

Answer
Hello Rich:

Soak the Carburetor. ****All the Carburetor Adjustments are the Same for Lawn Mower and Trimmers. There are Several Location for the Air Mixture Screws. The Idle Air Mixture Screws are Usually Located at the Top of the Carburetor Bowl and the Top of the Carburetor Body. If the Main Air and Idle Air Mixture Screws are Side by Side on the Side of the Carburetor, then the Idle Air is the Farthest from the Engine. The Main Jet Air Mixture Screw is Located in the Bottom of the Carburetor Bowl or Beside the Idle Air Screw on the Side of the Carburetor Body. Some of the Older Model Carburetors have the Main Jet Mixture Screw Straight in from the Top of the Carburetor Body (this is Rare anymore). If you have Cleaned the Carburetor (Disassembled and Soaked Overnight in Carburetor Cleaner (I Use Gunk). Then Blow Out the Passages with Compressed Air and Install a New Kit if Required. Now Setting the Air Mixture Screws:  ****Turn the Idle Air and Main Air Mixture Screws In Until SNUG **Do Not Jam** Then Reverse Both Screws 1 1/2 Turns. Holding the Throttle Full Open, Start the Engine. Turn the Main Air Mixture Screw Clockwise Until Proper Revs are Obtained. Occasionally you May have to Turn this Counter Clockwise to Achieve the Proper Revs. Now Allow the Engine to Idle. Set the Engine Idle Screw (Not Idle Air) so the Engine will Stay Running if Required. Now Set the Idle Air Mixture Screw so there is No Hesitation when Throttling from Idle to Full Throttle. Reset the Engine Idle if Required.**** Simply Spraying and Blowing Out a Small Engine Carburetor will Not Clean it. Soaking is the Only Way to Correctly Clean a Small Enngine Carburetor. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.outdoordistributors.com/ and Select the T. Then Select Tecumseh. Then Select Don't have Part Numbers. Then Enter the Model Numbers. Then Select your Model and Download the File for Online Viewing. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

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Respectfully

John