Lawn Mower Spark Plug Cross Reference (NGK, Champion & More)

NGK, Champion and Denso each number the same plug differently. This chart lists common small-engine plug numbers and the equivalent plug we stock, for mowers, trimmers, chainsaws and blowers.

What's in this chart: 63 plug numbers. We stock 24 of these OEM numbers directly and carry a Rotary or Oregon equivalent for 47.

How to use this chart

Find your OEM number in the first column (use your browser's Find, Ctrl+F or "Find on page"), then read across for the Rotary and Oregon replacement. Not sure of your number? Look up your machine by model and serial in our machine parts lookup.

How to read a spark plug number

Each spark plug maker uses its own code, so the same plug carries a different number from NGK, Champion and Denso. What has to match is the thread size and reach, the seat type, the heat range and whether it's a resistor plug. Always set the gap to the engine maker's spec, not the gap the plug came with.

Spark plug cross reference

Cross-references come from the aftermarket makers' published interchange data. Always compare dimensions with your old part before installing; machine makers sometimes change parts mid-model-year.

OEM or aftermarket?

OEM parts are the exact part your machine shipped with and the safe choice while it's under warranty. Quality aftermarket parts from Rotary and Oregon are made to the OEM dimensions and usually cost less. Many commercial fleets run OEM on drive components and aftermarket on wear items like blades, belts and filters.

FAQ

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