Champion RC12YC vs. 3071 spark plug

richard904April 3, 2008

I bought a Sears lawn tractor last year with the Kohler SV610 engine (21 HP). The spark plug model is listed on the inside of the hood - RC12YC which is different than the one listed in the manual. When I finally changed the spark plug, it had the Champion 3071. Are these equivalent and how do they compare? The 3071 was gapped at .030 and the RC12YC comes new with that gap. There is no information in the manuals for the gaps with these models of plugs. I presume the manuals cannot keep up with the model changes and engine permutations.

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I have always used Champs although I have had people tell me they wouldn't give me a nickle for a truck load of them..My current tractor uses the RC12YC and even with it burning oil I haven't had any problems with them.

    Bookmark   April 3, 2008 at 10:14PM
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So far, all I can find on the 2 plugs is that # 3071 is a Platinum "Super plug" version of the standard RC12YC plug which uses Copper. Interestingly, I found the gap listed as .040" for both plugs.

    Bookmark   April 3, 2008 at 10:41PM
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I carefully checked again the gap on my Champion 3071, and it is .030 inches. After a year of use, the spark plug is in very good shape. The only reason I would stay at .030 is that it ran well and came from the factory that way. An aerodynamics expert in detonation may know something about the reason for the different gaps, but Kohler should give clear instructions to the user about the spark plug options and proper gapping which may vary by spark plug type.

    Bookmark   April 4, 2008 at 10:37AM
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I went to the Kohler web site, and they have an owner's manual, "Kohler Courage SV470-610," which gives much more detail including a discussion of the spark plug options on page 11. The gap should be .030, and the Champion 3710 and RC12YC are allowable options. It is unfortunate that the "Operator's Manual" and the "Repair Parts Manual" we get with this equipment does not include this.

    Bookmark   April 4, 2008 at 10:59AM
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For what it's worth I've always replaced the plug with what the original was and never had any problems. Most of my small engines came with Champion.

My JD tractor has a Kohler engine. The JD manual recommends one gap and Kohler recommends another. 030" vs. .040" as best I remember.

    Bookmark   April 4, 2008 at 11:11AM
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I have a Sears tractor with a 16 HP Kohler Command Vertical crankshaft engine, CV16. It uses the Champion spark plug RC12YC, and the Kohler spark plug part number is 12 132 02-S. Unfortunately, there are conflicting data on the spark plug gap. The Sears tractor manual says 0.040" (p. 5). The freely available Kohler service manual at
says 0.030" (p. 1.10). I would suggest following the Kohler

    Bookmark   May 12, 2011 at 3:14PM
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