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Spark Plugs

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It started with a on 14 MM threads with a J-8, then a J-8C copper tipped J8 for better burning, then a CJ-8 the midget brother of the J- family came because of its lower profile. After that a J17-LM was used, not long, and superseded to a J19-LM and that is still the standard plug today, I think. All Canadian plugs are required to be resistor type, so there is a letter "R" in their somewhere. Sometime ago when the government was trying to tell everybody the right to way to formulate gasoline,and spark plug life went to heck. The then president of Champion wrote a letter saying throw all of the above in the junk and go to a CJ 14 if you encounter bad plug life. That's my story and that is what I am using now. Hardly change plugs now. By the way CJ-14's are at the high end of the heat level, maybe that's why.

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Bob, that probably helps with fouling too if your engine is burning a little. Funny, I have found if a engine runs bad and you changed the plug to try a second one. I have come accross more then 1 bad plug right out of the box!sm00

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The spark plugs asked about the J-17-LM and the J-8-c are compatible they are just different design ideas. the J in the numbers tell us that it is a 14mm plug the 1-25 tells us its for auto, small, and ordinance engines. the last part the LM means it is for lawn mower applications while the C tells us its just a copper design plug. the first letter is the thread and depth as a J is a 3/8 depth on 14mm threads the C is a 3/4 depth on 14mm threads.

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