Reply To: Sparkplug Neptune 15B2

[JOSEPH BRINCAT]

While we are on the subject of spark plugs… you may or may not know that the “J” sufix on obsolete Champion plugs indicated a plug that has a shortened ground electrode, where the ground electrode only extends to the center of the positive electrode. These plugs were intended to minimize carbon deposit shorting across the gap. You can convert any Champion plug to a “J” by filing back the ground electrode. I have heard that the “J” had its origin as in,  Johnson Outboard Motors… perhaps.

Joe B