Small Engines (Lawn Mowers, etc.): gas in oil, steering wheel puller, vent hole

Question
I own a craftsman LT 1000 riding lawn mower. It has a kohler cv460s 16 hp ohv engine with only 75-125 hrs on it. It recently started running gas out the muffler and will not start. It turns over but backfires and will not start while emptying the gas tank out the muffler. I checked the oil and it had gas mixed in with the oil so I change the oil, new spark plug, cleaned air filter, checked and cleaned the carb. There was no debris in carb. bowl in or around the needle and needle/float seemed to work correctly with no gas inside float. I started the mower but it ran rough and the muffler started glowing very red in color.  When I crimped the fuel line it stopped glowing and ran a little bit better    so I turned the engine off and not knowing to much about this engine I started checking the more simple things like the spark plug, it was wet with gas wiped it off checked for spark seemed blue and ok. Still very hard to start if at all and still backfiring. I bought a new walbro carb. installed it and same exact thing except no gas out the muffler, muffler did glowed red, smoked pretty good so I shut it off. Checked vent hole in gas cap ok their, new carb was full of gas and park plug was wet with gas. Seems to be out of time or not firing correctly. Can you please give me some simple checks that I can do to find the problem.
find problem  
spark seemed ok and so far no gas in oil again


Answer
Hello Charles:

Check the Flywheel Key. If the Key is Damaged it will Change the Spark Plug Timing, the Engine will Backfire and the Muffler will Turn Red. To Check/Replace the Flywheel Key; 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). A Blown Head Gasket Between the Valve Push Tubes and the Cylinder will Cause this Also. The Only Sure Cure to the Gas in the Oil is to Install a Manual Shut Off Valve in the Gas Line and Manually Turn Off the Gas when the Engine is Not in Use. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model Numbers. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. 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 9pm EST (US). My New Day Starts then. Thanks.

Respectfully

John