Plug Readers Chime In

These look okeh, but I like the previous pic a little better (in post № 25)—if the engine wasn't pinging or giving other signs of excessive timing advance, I'd put back those 2°.

(Probably ZFR5N; a 4 would be one step hotter and a 6 would be one step colder, but I'm pretty sure there's no ZFR4N or ZFR6N.)

Thanks, that was a typo, and your are correct.

I'll run them a little longer at 2 degrees retarded, then check all of them again soon.