Spark Plug GapperDescription The FuelTech spark plug gapper is recommended for the adjustment of the distance between the center and ground electrodes. Description Save time and precisely gap your spark plugs with our new billet spark plug gapping tool. To use, simply place spark plug as shown in the picture and insert desired feeler gauge between ground strap and electrode. Turn knob clockwise until the ground strap is tightly pressed against the feeler gauge. Then