In Reply to: Which up-dated spark plugs for my 8n? posted by Jeff in Maine on October 03, 2020 at 19:48:45:
Congratulations.
You have confirmed that even when you give them a part number, many parts clerks are clueless as to the basic functioning of the part.
You need a hotter heat range plug in the tractor because it is not used on a daily basis.
That would be a Champion H-12 or Autolite 437.
ANY plug in that heat range will work better than ANY plug in the colder heat range of the H-10 or........the 216.
You can get the 437's at Advance.
You can also use the NGK B4L plug.
NGK 3112 (B-4L)
http://www.stoutracingengines.com/2014/pdf-heatrange.pdf
https://www.ngk.com/product.aspx?zpid=9221
https://shop.advanceautoparts.com/p/autolite-copper-non-resistor-spark-plug-437/3290492-P