I also am expeiriencing noise interference with my rcs 1.4. I would like to note that the sheildings path to ground is not only at the circiut board, but also at the spark plug cap. the outer metal shell of the cap directly connects to the outer portion of the spark plugs wrench flats, which ground to the engine. you can prove this with a resistance check on a meter.
I am finding evidence of arcing from the inner high tension lead at the spark plug to the outer metal sheild cap of the spark plug boot. Electricity always takes the least path of resistance. the planned path should be accross the electrode. but if it can find an easier way like the sheild, it will take it.
does the hose clamp trick really do it? Or is there a better fix? like a different style boot?