I recommend using a NGK BKR5EIX pt. # 6341 spark plug . IT will last 8 - 10 years depending on the hours per week it is used, commercially a good 5-6 years . The other problem is the fuel filter. An in line filter like a NAPA 3012 will filter out the the trash that the factory screen filter allows to get to the carburator. The carburator is another problem as water gets is the gas much quicker . Take bowl loose with a long pair of needle nose pliers & clean if bowl leaks gas may need to get the 2 gaskets to bowl. Make sure you have your model # . Fuel is another issue as there is more alcohol in gas these days . Premium gas may help if you don't use daily BUT the product that I have found that works best to disperse water in gas is REDLINE SL-1 fuel additive. 1 ounce per gallon will make the alcohol & water disapear. Exception to this would be when you see water on the bottom of the tank . In this case drain the tank first before cleaning the bowl of Carburator . Just a reminder to never leave the switch on when the motor is not running . Most 14.5 B & S have an electric switch that allows fuel to go through carburator when switch is on. If that does not fix your problems you have a spark issue , a valve clearence adujst hot or cold ? or broken connecting rod . Mechanical issues should be taken to a specialist !

Very good points. Thanks,Ewalk! My mower feels as if it has compression release allowing the easy spins. It is the initial seasonal start-up my arm hates and fine with the pull afterwards. “A Big Safety Issues” if you have ever had a “Kickback”, it could take you out. I doubt the none experienced would make the needed Jig. If an electric motor can be adapted to your mower or Etc. that is the safer way to go. The neatest I have seen is the mower that re-coils for the next start when you kill it. Again it could be mean and not start with that charge at the start of the season. Hopefully it will have Compression Release to assist with one or two pulls. If I was not so lazy I would hire or trade with my Yardman, LOL! He walks from 10 houses away with his problems. I call him from 10 houses away when I need Help. Or! Alert him on my 2 mi walk I’ll need help on my return if he has time. He’s a good yardman with yards and helps in a crew…

Good chance that backfire caused the engine's flywheel key to partially/fully shear, throwing timing off. If you are sure of good fuel flow and presence of spark, would download the free service manual from the Kohler website for that engine and give it a go - if you are the shadetree mechanic type. OTW,, shop time. If you do pull the flywheel, make sure all is pristine clean before reassembling and torque to spec...good luck.

I'm helping a lady friend with her Troy-Bilt lawn tractor. It has a Kohler 22hp Courage engine that starts right up every time and then shuts down immediately just like the key has been turned off. This tractor has a 'reverse' safety circuit key position on the ignition switch. I discovered that if I turn the key back and forth between the 'reverse' position and the regular 'run' position, before the engine actually coasts all the way down, the ignition switch seems to make contact and the engine rpm will pick back up and the engine will stay running with no further issues until you turn the key to the off position - then you start over again the next time you try to start-up. I thought the ignition switch was faulty and replaced it, that was not the solution - the problem still exists. It should probably be noted that on rare occasions, the engine will actually start and stay running with a normal twist and release of the key.