Small Engines (Lawn Mowers, etc.): Garden Tiller loses power and dies, garden tiller, valve clearance

Question
I have a Honda Harmony Tiller/Cultivator.  It starts right up and has plenty of power, but after about 5 or 10 minutes of use it loses power and dies.  Then you have to wait about 15 minutes before you can use it again and then it does the same thing again loses power and dies.  What is the problem?  How can I fix this problem?

Answer
 Hello Randy:

 1- Make Sure the Gas Tank Cap is Venting the Tank Properly. However 15 Minutes is the Usual Amount of Time that it takes for the Tank to Build a Vacuum and Stop the Gas Flow if the Cap is Not Venting the Tank. 2- Change the Gas Filter(if there is one). 3- Check the Compression. If the Valves need Adjustment; as the Engine Heats Up the Valve Clearance Shrinks and the Valves Don't Seat Completely and the Engine will Slowly Lose Compression and Power and Quit. 4- Bad Rings will Also cause this Problem. Is the Engine Slowly Losing Power and Quiting or is it Quiting like the Spark to the Plug was Stopped? Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John