Small Engines (Lawn Mowers, etc.): Kawasaki 14HP Backfire, question pool, faint smell

Question
My JD LX176 lawn tractor has a 14HP Kawasaki (code# FC420V-AS10).  It has run flawlessly for 14 years and I maintain it well.  Recently, it has developed a starting issue after the engine has operating a while.  After running a while and then shutting down, it will not start again until the engine has cooled (for at least an hour).  Operating the starter when the engine is hot produces a backfire and there is a faint smell of raw gasoline so there must be some flooding.

Can you give me some suggestions on what to try before I start taking things apart?

Answer
Hello Dan:

Sorry for the Delay. This Question was Located in the Question Pool and I can Only Answer Questions from the Question Pool when I am Not Answering Questions here or at the Other Site I Answer Questions at. You can View a Breakdown/IPL of the Engine and Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers and Click Find. Then Select your Model from the Search Results Area. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. This Problem can be Caused by 1 of the Following. I Give the Most Common Cause First and So on. You May Want to Perform the Checks in a Different Order. 1- The Ign Coil is Heating up. On this Model JD, to Check the Coil, Remove the Blower Housing (metal Engine Cover) and Disconnect the Cut Off Wire from the Coil. Remove the Spark Plug/s and Wrap a Wire Around the Threaded Area of the Plug/s. Attach the Other End of the Wire to the Engine Block. Turn the Engine Over and Watch for Fire at the Plug/s. If you have Fire, then a Safety Switch is Bad of there is a Ground in the Wiring Harness. If No Fire at the Plugs, then the Ign Coil is Bad and Requires Replacing. You can View a Breakdown/IPL of the Engine and Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers and Click Find. Then Select your Model from the Search Results Area. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. To Check the Safety Switches; The Following is an Instruction File for the Safety Switch System. Any Input is Appreciated. The Color Code of the Wires May be Different than those I Use as a Reference in the Instruction File. **PLEASE REMEMBER THAT THE INSTRUCTIONS FOR CHECKING THE SAFETY SWITCHES IS JUST THAT!!! FOR CHECKING ONLY. I NEVER Suggest a Mower be Operated with a Safety Device or Switch Disconnected or Bypassed. Now. On Some Model Mowers you can Simply Unplug the Safety Switch from the Harness. On Other Models you have to Place a Jumper Wire Between the Harness Terminals (on the 4 Post Switch (Clutch/Brake) Jumper from Same Color Wire white to White First and then Check for Fire, Now Include the Black to Black Wires if No Fire. Check the Clutch/Brake and the Blade/PTO Safety Switches First. Check the Seat Safety Last. Usually the Seat Safety is Not in the System for Starting the Engine. Just to Ensure Someone is in the Seat when Engaging the Transaxle and/or Blades. Use a Paper Clip or a Short Wire to Make a Jumper.**  2- The Carburetor Solenoid is Heating Up and Restricting the Gas Flow to the Jet. The Engine then Requires 3 to 4 Intake Strokes to even Attempt to Start and Usually you Get the Backfire through the Carburetor Due to Hot Gasses Inside the Cylinder Igniting as the Next Air and Gas Mixture are Entering the Cylinder. The Gasses Ignite while the Intake Valve is Open. The Following is a Basic Instruction File I made for Checking the Carburetor Solenoid. Any Input is Appreciated. **Check for Current/Voltage (10.5 VDC Minimum) to the Carburetor Shut Off Solenoid. If the Carburetor Shut Off Solenoid has Current, then On Some Solenoids you can Remove the Needle and Replace the Solenoid to Test them. ****PLEASE DO NOT OPERATE THE MOWER WITH THE SOLENOID BYPASSED IN THIS MANNER. THIS IS "ONLY" FOR TESTING.**** For Others, Remove the Carburetor Solenoid and Go to the Hardware Store. Purchase a Bolt of the Same Diameter and Threads.It Needs to be 1/2" to 3/4" Long for the Horizontal Mount Solenoids and 1/4" Long for the Vertical Mount Solenoids. Put this Bolt in Place of the Solenoid. If this Corrects the Engine Problem, then Replace the Solenoid. ***NOTE: THIS IS FOR CHECKING THE SOLENOID ONLY I NEVER SUGGEST YOU OPERATE THE ENGINE WITH THE SOLENOID OUT OF THE CARBURETOR EXCEPT FOR TESTING PURPOSES*** Sometimes the Plunger is Moving, Just Not Far Enough to Allow the Gas to Enter the Jet.**  3- A Sheared Flywheel Key. Over Time the Flywheel Nut May Loosen Due to Vibration and Heat Expansion and Contraction. When this Happens, the Flywheel Usually Damages the Key when the Engine is Shut Off. The Sudden Stop will Move the Flywheel Enought to Cause the Damage. A Steering Wheel Puller can Usually be Used to Apply Enough Pressure to Remove the Flywheel. The Following is the Instruction File I Made for Removing the Flywheel from Most Mower Engines.  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 Coil. 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. *** Be Sure you have the Flywheel Torqued to the Proper Torque (I require the Model and Spec/Type Numbers Off the Engine to Provide the Proper Torque) and Set the Coil Gap to .020in.. 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