Lawnmowers Parts 2 (Two) Genuine Champion Spark Plugs RC12YC Replaces Kohler 12 132 02-S;M78543

What It Is

The Lawnmowers Parts 2-Pack of Genuine Champion RC12YC Spark Plugs replaces Kohler part numbers 12 132 02-S and M78543. These are standard copper-core spark plugs designed for small engines in lawn mowers, tractors, and other outdoor power equipment.

Fitment & Compatibility

• Check your engine brand: These plugs are a direct replacement for many Kohler engines (e.g., Command, Courage, and single-cylinder models). Verify your engine’s specific plug gap requirement (typically 0.030” for RC12YC) before installation.
• OEM vs. aftermarket: These are genuine Champion plugs, not generic knock-offs. They match the heat range and thread size (14mm thread, 3/4" reach) of the original RC12YC.
• Measure thread reach: Ensure your engine’s spark plug hole depth matches the plug’s 3/4" reach. A too-long plug can hit the piston; too-short can cause misfire.
• Cross-check model numbers: Confirm your engine’s manual lists RC12YC or comparable numbers like J19LM or RJ19LM. Avoid assuming all Kohler engines use this plug—some use longer reach or resistor plugs.

Key Things to Know

• Quality: These are genuine Champion plugs, not generic budget plugs. Copper core offers reliable performance but has a shorter lifespan (around 100 hours) compared to iridium plugs.
• Installation: Easy for DIYers—just gap to 0.030”, hand-tighten, then torque to 15-20 ft-lbs (or 1/4 turn after snug). Over-tightening risks stripping the aluminum head.
• Common gotchas: Old plugs can seize; use anti-seize on threads if your engine is aluminum. Always replace in pairs for twin-cylinder engines.
• Price value: At $8.25 for two, this is cheaper than buying individually at auto parts stores. Great for replacing both plugs in a twin-cylinder mower or keeping a spare.

Should You Buy It

If you own a Kohler-powered mower, tractor, or generator that calls for RC12YC plugs, this two-pack is a cost-effective, reliable choice. It’s ideal for routine maintenance—just double-check your engine’s plug gap and reach. Avoid if your engine requires a different heat range or longer-life iridium plugs.