Would switching to BR9EYA plugs from BR9ES plugs create any sort of problems? They are about 2mm longer on the electrode.They won't touch the piston,but would the extra lenght cause other problems?

I wouldn't think so. The EYA's are just suppsed to have less fouling. I thought the only difference was the little groove in the electrode. As long as it doesn't hit, 2mm shouldn't make a difference.

I read a report last year, which said that even though the eya's are the same rating, that in fact they run a little hotter, and the switch was not recommended.

Don't recall where that was, but you might want to check the NGK website first.

FishHog

I looked into the same thing last year and came away with no clear answer.