Champion rc12yc, Briggs 491055 or Champion Premium plug (platinum) #3071
a ngk cr7hsa spark plug
.030"
Rj19lm
ngk Bm6a its the same plug
.030"
Spark Plug gap is .025
Rj19l
bp4 ngk
Spark plug gap should be .025 http://store.chainsawr.com/
Champion CJ8 spark plug is for the crsftsman 3.0 edger/trimmer
on the back of the plug package it has : replaces CJ8, RCJ8, J19LM & RJ19LM. hope this helps.
ngk Bm6a its the same plug