a ngk cr7hsa spark plug
ngk Bm6a its the same plug
bp4 ngk
on the back of the plug package it has : replaces CJ8, RCJ8, J19LM & RJ19LM. hope this helps.
ngk Bm6a its the same plug
Champion J19LM or RJ19LM
Looks like the RJ19LM
The replacement is a Champion CJ-8
64 Autolite Replaces Champion RN11YC, NGK BPR5ES
Champion rc12yc, Briggs 491055 or Champion Premium plug (platinum) #3071
PTR6F-13
If your spark plug doesn't screw in your threads might be messed up. Run down to your local Part store and ask for a Thread Chasser($arround 10$) and screw that in to your spark plug housing just as you where screwing in a spark plug. What this does is it replaces the threads. Take out the chasser, Lubricate your spark plug and you should be good to go.