Small Engines (Lawn Mowers, etc.): Very Loud/Strong 15.5 HP Kohler backfire, air filter element, hydraulic lifters

Question
Yesterday my 15.5 HP Kohler issued a loud/strong  backfire when I tried to start it.  So loud that my wife came out of the house to investigate it!  Following this event it would crank but not start and made a tah-tah-tah-tah pneumatic sound with each revolution.  I let it "rest" for a few minutes and it then started and ran normally for an hour while I cut the grass.

My friend's theory is the the explosion was strong enought to deflate the hydraulic lifters, thus causing the tah-tah-tah-sound with the valve(s) open, and then corrected itself when the lifters filled with oil.

I arbitrarily changed the oil and oil filter and installed a totally new air filter element and pre-filter.  The engine seems to run fine now.

I am still curious as to how it "fixed itself"?

Thanks,

Felix  

Answer
 Hello Felix:

 Did the Oil have a Gas Smell to it? Most times this Problem is Due to the Carburator Float Needle Not Stopping the Fuel from Flooding the Engine when the Mower is Not in Use. Your Friends Explaination was Close. Actually the Lifters were Inflated After the Backfire and the Noise was the Compression Escaping by the Valves. When you let it Rest, the Lifters Deflated to there Normal Position and the Engine then Started. I Suggest to All the Riding Mower Owners to Install a Shutoff Valve in the Gas Line and Turn the Gas Flow to the Carburator Off After Each Use. Hope this Helps. Let me know what Happens, Please. I enjoy knowing the Outcome. Thanks.

 Good Luck

 Respectfully

 John