Is this normal...
 

Right just got a new set of plugs, coils & leads on the renesis (one of the trailing coils failed) took her out for a blast & then return about 20 mins later, thought i would take the plugs out to see what they were like, the trailing plugs were fine but the leading were very darkened/sooty considering i had ony just put them in & went for the one run, is it normal for the leading plugs to be in such a different state to the trailing plugs?

Thanks James.

Yes... that is normal

Thank you.