Small Engines (Lawn Mowers, etc.): Spark out exhaust at end of shut-down, recoil starter, starter rope

Question
Tecumseh OVRM120

I have adjusted the carburetor, although the engine was not very sensitive to adjustment.  Main adjustment is not under the bowl, but above and to the side.  The carburetor seems very clean, but I have no experience in this.  Perhaps I need a carb adjustment manual.

The engine runs fairly well, but I sometimes get a some initial resistance from the recoil starter rope.  Also, there is a good spark and pop coming out of the exhaust as the engine comes to a halt when I shut it down.  At times, smoke emits from the exhaust for 20 or 30 seconds after startup.  

The blade key is not sheared, but I have not checked the flywheel key, because the engine runs well once started up aside from what I mentioned.

Answer
 Hello Mark46:

 Clean and Rebuild the Carburator First. Soak the Carburator Overnight in Cleaning Solution(Gunk carburator cleaner) and then Blow Out the Passages with Compressed Air. Install Kit. You can View a Breakdown of this Engine at this Addy http://www.outdoordistributors.com/ and Click on the T. Then Select Tecumseh. Then Select Dont have Part Numbers. Then Enter the Model Numbers and Click Go. Then Select your Model from the Search Results. This will Download a Breakdown/IPL of this Engine. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John