Champion (973) RJ19HX Racing Series Spark Plug, Pack of 1

I put this in my briggs lawn mower with the 6.75 HP motor from 2005 and it works good.I have never herd of putting a raceing plug in a lawn mower but it honestly seems like any other mower plug.It was allready pre gapped ay 0.30 for my motor.I but you may have to adjust it for your own motor.

Crank times on my 10-year old MTD lawn tractor (16-HP Briggs twin) on cold starts were getting long--time for a tuneup. I was looking for the "stock" RJ19 plug and ran across these at about the same price. The "racing series" description still cracks me up--main difference is that this is an extended tip plug, like all cars have used since at least the 1960's. My mower starts great and runs smoother now. Not sure how much different it would be with new "stock" plugs, but the simple improvement in this plug's design at no cost makes me feel better about the repair.

A word of caution--depending on where the plug is installed in the combustion chamber, I suppose there could be some flat-head engines where the extra plug tip length could cause interference between plug and engine block or piston. My plugs were installed in the "end" of the chamber near the valves, with the tip pointed down the "long side" of the chamber, so I could see that interference was impossible...Read more

This Champion Spark Plug RJ19HX is required my the engine manufacturer of my Sears lawnmower. Who would have thought that a regular R19LM would not have worked??? The local Sears store that sold me this lawnmower said this plug was discontinued, and even no longer being manufactured. Well I got the RJ19HX through Amazon put it in my lawnmower and went about mowing my yard. Sometimes it pays to read the instruction manual. Oh yes, I ordered two of these sparkplugs through Sears Online Parts and received them. Therefore I only have one last trip to make to my local Sears store...to show the Sears employee my collection of the no longer manufactured sparkplugs.