replace battery & starter solenoid.. possibly carb.
John Deere makes good lawn mower replacement parts. I would probably go with John Deere or Honda spark plugs, if I had to make a decision on what brand to get.
Valve guides are worn and piston rings are worn crank case oil seeping up to spark plug fouling them change spark plugs or try irridum plugs they sometimes work in engines that consume oil.
NGK platinum plugs
Run out of gas? check spark plugs? I would push it into the garage and call someone who knows about them.
The spark plug gap for a Murray 12 hp riding lawn mower should be set at .020 inches. This is equal to .5 mm.
Bosch spark plugs has been a reliable brand. And many auto parts stores and auto mechanics would recommend them. Some Bosch spark plugs come with a warranty.
.20
How long spark plugs last depends on the brand of spark plug and the condition of the car. In a well maintained car, some spark plugs will last from 3 to 7 years.
If the mower starts and runs - but is constantly making little "misses" - suspect the plug first of all.
Champion
I am assuming that the mower doesn't start.... My first guess would be that you are not getting spark to ignite the gas in the engine. Check to see if you have spark at the spark plug.
Would you use lawn mower plugs in your car?? NO!!!!