What Does F6TC Mean on a Generator Spark Plug Instead of F6RTC?
The code F6TC marks a spark plug with a 14mm thread, a 3/4-inch reach, and a projected core nose, while the missing R means it lacks a built-in resistor. The R in F6RTC stands for resistor, a ceramic part that suppresses radio frequency interference. I learned this the hard way when my generator kept fouling … Read more