i have been using ngkzfr5f plugs to break in a new engine
i experienced high speed glazing yellowish tint and i switched to colder plugs

i now run a kj20cr-l11 and i have no glazing but when i sprayed a 50 shot on a
brand new set i pulled the plugs and noticed the spark was arcing hard on the ground strap very close to the base of the plug infact as close to the base an possible

am i running lean
or am i advanced
or do i just need to go to a colder plug?
please help i don't have any experience reading plugs