Small Engines (Lawn Mowers, etc.): Craftsman 22, craftsman lawn mower, varnish

Question
I bought a Craftsman Lawn Mower about a month ago in a garage sale for $75. It looked brand new. I brought it home and mowed w/it the first day w/o any problems. My husband used it a few days later and it died on him twice. The next time I used it, it died on me after about 2 minutes and then it was hard to start. We replaced the spark plug and let it run on the driveway for about 10-15 minutes to see if it would die (it didn't). We've added stablizer to the gas in case there was any varnish. The next time I mowed w/it, it died, but restarted and I mowed the whole yard. I went to go mow this morning and it started, mowed for about 1-2 mintutes and then sputtered and died. It is so hit and miss. Any ideas what might be going on? I REALLY appreciate your help and any insight you may give.  

Answer
 Hello Terry:

 Two things come to Mind. 1- How long did the Mower sit before you Bought it? The Carb may Require a Good Cleaning and Overhauling. If Varnish did Break Free, It is Probally Causing the Problem. 2- The Other Possible Cause is the Ignition Module. If it is Reacting to the Heat of the Engine, it may Ground and cause this Problem. I suggest the Carb First. Normally the Ignition Module will not Restart until the Engine Cools Enough for the Ground to Close back up. The Module on most Mowers is a Part of the Coil. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John