You best look at the engine first. The plug is located under the black rubber hood attached to a black rubber wire going into the bottom of the cover over the engine fan.
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On my old riding mower (Craftsman), I found it on the very front of the engine exactly opposite of the rider. Two big screws, one on each side, allows the whole cowling to come off. Once the cowling is gone, it is very obvious.
The spark plug gap for a Murray 12 hp riding lawn mower should be set at .020 inches. This is equal to .5 mm.
.20
RC12YC Champion
take the spark wire off, remove spark plug, put wire back on plug, put steel part of plug against the medal part of engine (with a insulated pare of pliers) then crank the motor over watch the electrode on end of plug if you see spark you have it if you don't ....
Should be 5/8
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.
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remove the old spark plug and either take it into your local garage and the guy behind the desk will find you the replacement, or right down the type of spark plug (found on the side of the plug) and go to the NGK website and you will find the replacement on there, The above advice is if you have the previous spark plug, should you not, your best bet would be to go to the manufactures website for the engine and look up for engine failing that take the mower to your local garden equipment service engineer (yellow pages) and they will find you the correct spark plug.
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.
Yes
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