I am reviving this briefly. The author said he is using the E3.10 but it is too small. The proper replacement for the B6HS is the E3.32.
"E-3 Sparkplugs Small Engine Spark Plug Model E3.10 Champion J17lm , J19lm , J8c , Ngk-B4lm , B6sr4lm"
"E-3 Sparkplugs Small Engine Spark Plug Model E3.32 REPLACES: Champion L78C, L82C, and RL82YC; NGK B6HS, B7HCS, B7HS, B8HS, and B9H"
I bought the 3.10 and it is very short thinking it was the right one. The cap covers the entire ceramic portion and is almost impossible to pull off!