Losing my marbles, plug type for Farmall A

Is champion UD16 plug too hot for Farmall A for plowing snow? Would not start after I guess flooding it, and I put these UD16 plugs in. Old ones were D21 but used to cut lots of grass in the summer with it. Thanks for helping out old man. Dave

if i don't have my numbers mixed up on champion plugs the higher the number the hotter most people have misconceptions on heat ranges,some are scared of hotter heat ranges fearing engine damage,if your was running ok with the 21 range then switch back,a plug chart showing what effect heat ranges have on a plug would make it easier to understand, the whole purpose is to get the range that's cold enough that it won't damage the plug from high operating temperatures in the cylinders under heavy load and high rpm, on the other end of the spectrum is one hot enough to prevent carbon fouling from low cylinder temperatures ,low rpms ,slight oil usage, ect.and but not hot enough to damage the plugs cause denotation and a few other problems,use to work for an outfit that their mechanics at the garage would tune up a truck with a 427 engine using 10 range plugs, which was fine on a good engine being run on the road at high speed ,but shortly after arriving on the job site they would start killing spark plugs due to low rpm operation, less engine loading and long idles i have used as high as a 17 heat range to prevent fouling. would solve the problems until they went back to the shop and got tuned up again because the manual recommended 10's and that's all they would use

i use autolite 3116.

Hurl them U series Champions in the junk barrel, they are prematurely aging you. Use non resistor Autoloite 3116.

Was not on Ih but Deere and that 16 is a mid range plug and on the Deeres hard plowing 10 hours a day never took out the hotter D21 plugs at any time and no problems, that was before Champians became junk and when with AC plugs you put new plugs in when you went out to work in the morning, again at noon and again after the evening meal, after doing that for a few times got some when TSC had their own brand and did not touch the plugs again for 2+ years.