I’m using NKG B9EGV plugs in my 20B, based on Paul Yaw’s recommendation, with apparently good performance.  They now have 20-25 hours since installed through all the dyno runs, engine tuning and some flying.  I took them out for a look and they have a bit more deposits than I expected, and some areas nearly black.  The electrodes still look OK, and the gaps are still close to .025 as initially set. 

I have been doing a lot of re-tuning of the mixture which may account for some of the dark deposits, but I’m considering a change of plugs soon.  Just wondered what other recommendations might be out there regarding plugs, heat range, gaps.  Lynn; I recall you weighed in on this before, but I didn’t find it in the archives.

Thanks,

Al