Small Engines (Lawn Mowers, etc.): Engine trouble, blown head gasket, craftsman riding mower

Question
Hi John!  I own a Craftsman riding mower with an 18 hp. Kohler engine Model MV18S.  I began to have trouble with the mower last fall.  At first it seemed as if it was not getting enough fuel and I changed the fuel filter and disassembled the fuel pump believing there may be an obstruction.  I dropped the bowl on the carb and cleaned out the dirt.  After reassembling everything the mower ran great for about an hour.  Then it began to crap out and back fire.  It was necessary to pull out the choke to keep it running.  It continued to run very rough until it stalled.  After cranking it for a few seconds it would start up and run for about 5 minutes and then do the same thing again.  I am sure that it is getting fuel.  Do you believe I may have a problem with the rectifier-regulator???  Or do you think it may be something inside the carb???  Any help would be greatly appreciated.  Thanks!

Answer
 Hello Chet:

 If you can Use the Choke to Maintain Engine RPMs, then Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner. Then Blow Out the Passages with Compressed Air and Install New Kit. It the Carburetor Cleaning and Rebuild Doesn't Correct the Problem, then Check the Compression. A Blown Head Gasket will Cause the Same Problem Depending on when the Blow is at. You May be Able to View a Breakdown/IPL at this Addy http://www.kohlerengines.com/service/manuals/index.jsp and Follow the Instructions to View a Parts Manual (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