Small Engines (Lawn Mowers, etc.): tiller motor wont start, bringing it home, rototiller

Question
I bought a used Kubota tiller last weekend.  The tiller is 12 years old and had not been started for 10 years.  Unfortunately the previous owner left gas in the tank which had gummed up and smelled like turpentine.  The fuel cock was turned off.  Upon bringing it home I cleaned out the tank and fuel line a minimal amount, cleaned the air filter, sprayed carb cleaner in the air intake and spark plug hole.  To my disbelief, the motor started right up.  I ran it for about 10 minutes and it died on its own.  The next day I carefully cleaned out the tank, removing a huge amount of gunk.  I replaced the fuel line and had to clean out the fuel cock again too as it had reclogged.  However, I couldn't start it again.  This evening I again disassembled the fuel line and also removed and cleaned out the carburator (pretty minor amount of crud). No luck.  The motor coughs just a little bit but doesn't catch.  I've used multiple choke and throttle positions, I've checked that there is a spark, and the plug looks wet.  I haven't replaced the sparkplug yet.  What could be the problem?  Any help appreciated.  

The rototiller is a Kubota AT70S with a 7HP Kubota GS-280TE motor.  

Answer
 Hello Jim:

 Check the Spark Plug for Fire. If the Plug is Firing, thne Clean and Rebuild the Catburator. Soak the Carburator Overnight in Cleaning Solution and Blow Out All Passages with Compressed Air. Hope this Helps. Let me know what Happens, Please. I enjoy knowing the Outcome. Thanks.

 Good Luck

 Respectfully

 John