https://ugpus.com/product/champion-spark-plug-compatible-with-john-deere-m78543-m87543-rc12yc-oem-fits-gas-engine-motors-high-performance-nickel-alloy-copper-core-durable-replacement/
Champion-Spark Plug Compatible with John Deere M78543 M87543 RC12YC OEM Fits Gas Engine Motors...