Small Engines (Lawn Mowers, etc.): mitsubishi generator, gas vapors, mitsubishi generator

Question
I HAVE A MITSUBISHI GENERATOR THAT WHEN IT GOES FROM HIGH IDLE TO LOW IDLE IT SHUTS OFF, ALSO WHAT CAUSES IT TO BACK FIRE.
THANK YOU

Answer
 Hello Rick:

 Most Times the Problem you Described is Caused by 1 of 4 Things. 1- The Carburator Idle Air Jet is Clogged. Remove and Disassemble the Carburator and Soak Overnight in Cleaning Solution(Gunk carburator cleaner). Then Blow Out All the Passages with Compressed Air. Install Kit. 2- Low Compression at Low RPM's. Engine Requires Re-Ring (Rebuild). 3- Valve Lash Incorrect. Reset the Clearance Between the Valve Stem and the Valve Tappet/Rocker Arm. 4- Check the Exhaust Port and Muffler for Blockage. Check the Spark Arrestor Srceen Inside the Muffler for Blockage. The Backfire is Caused when Unburnt Gas Vapors Build up in the Muffler and when you Shutoff the Engine Cold Air Causes these Vapors to Ignite Inside the Muffler because of the Hot Carbon on the Exhaust Valve acts as a Heat Source. The Engine Running too Rich from the Carburator, Low Compression or The Valve Lash Adjust will cause this Problem. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John