Small Engines (Lawn Mowers, etc.): Lawn mower engine stopped running smoothly, Briggs Carburetor Cleaning and Governor Reset

Question
Hi,
I have a lawn mower with a 3.75HP Briggs and Stratton (Sprint) engine. It was running perfectly fine until one day I accidently ran it over a fallen fruit from my orange tree. The orange was clearly cut by the rotating blade but following this, the mower engine has been revving up and down and blowing smoke (with a strong smell of gas). I cleaned the spark plug and air filter but the problem has not gone away. Is this a carburetor problem?
Thanks for the responses in advances.
Ram

Answer
Hello Ram:

1- The Blade May be Loose and Requires Tightening. Tighten the Blade Bolt. 2- The Flywheel Key May have been Damaged. The Following is the Instruction File I Made for Correcting this Problem. It is the Basics and if you have a Question, Please Ask. Any Input to Make this File Better is Appreciated. ***Disconnect the Coil Wire from the Spark Plug. Remove the Blower Housing (metal engine cover). Remove the Flywheel Nut or Starter Cup (Depends on the Model). Now Attach a Steering Wheel Puller to the Flywheel Using the Threaded Holes in the Flywheel. Tighten the Puller. Now Hit the Puller with a Hammer. Repeat this Procedure Until the Flywheel Pops Up or can be Lifted Off the Crankshaft. On Some Models you Can Not Use a Puller and Must Use a Pry Bar and a Pipe Cap that is Slightly Larger than the Crankshaft. Place the Pipe Cap Over the Crankshaft to Protect it. Place the Pry Bar Under the Thick Section of the Flywheel and Pull Up Against the Flywheel. **BE CAREFUL  DO NOT PUT A HOLE IN THE BLOCK UNDER THE FLYWHEEL** Now Hit the Pipe Cap that is on the Crankshaft (covered with the Pipe Cap). Repeat the Procedure Until the Flywheel can be Lifted Off the Crankshaft. *** Now Replace the Key Between the Flywheel and Crankshaft and Reverse the Procedure. Be Sure you have the Flywheel Torqued to the Proper Torque. You can Locate the Proper Torque for the Flywheel Nut or  Starter Clutch at this Site Addy; XXXXXX and Select Your Engine Model from the List Provided. 3- The Governor May have Slipped on the Governor Shaft and Requires Resetting. The Following is an Instruction File I Made for Making this Adjustment. Any Input is Appreciated.  If you Removed/Loosened the Governor Arm to Remove the Carburetor, then Reset the Governor. **To Reset the Governor; Loosen the Governor Arm Bolt and Turn the Governor Shaft Clockwise Until it Stops. Using the Governor Arm Hold the Carburetor to Full Throttle. Now with the Shaft Full Clockwise and the Governor Arm and Carburetor Held at Full Throttle, Tighten the Governor Arm Bolt. If the Engine Still Runs Full Throttle, then Reverse the Rotation of the Governor Shaft, but Still Hold the Carburetor at Full Throttle with the Governor Arm. If it Still Runs at Full Throttle, then Check the Internal Governor.** You can View a Breakdown/IPL of the Engine at this Site Addy; http://www.briggsandstratton.com/maint_repair/manual_and_more/doclist.aspx?categ... and Enter the Model Numbers (XXXXXX) and the First 4 Type Numbers (XXXX) in the Appropriate Boxes and Click GO. Then Select Download PDF. 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

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John