NGK BPR7ES

Thats the type of spark plugs I now use!
Previously I ran the same type without the R (BP7ES) and it was fine with carbs. Now that I converted to injection, these no longer work. The difference is quite spectacular: rough idle, idle remains not constant when warming the engine, bad combustion a.o. After I rebuilt the engine it ran ok but had some backfire on idle when warm. Checking with Dave Walker, head of Emerald ECU, he recommended to use the "R" plugs. Now the engine runs a charm ... fingers crossed it will do for a long time.
This is mostly due to RFI (radio frequency interference) generated together with the spark. No harm for carbs, but as soon as electronics are involved, it matters.

Gap is set to 1mm. Have a look at above chart if you travel through both imperial and metrical worlds.

Once the engine is run in, I will do a power blat and check the spark plugs colour. Only then I will proceed to more tweeking of the ECU settings (ignition and fueling).
Cheers.