Re: I Want Reliability
The stock plug wire is suspect, too. It's made in a toy factory from 6 parts to replace what is made here from 3. The inside parts come apart very easily and can work intermittently.
Spark plug, BP5HS "P" is for projected tip. "5" is the hottest recommended plug and the projected tip keeps it cooler. A B6HS is the coldest plug I'd run in a stock motor but there could be some fouling from there colder. Colder plugs are for when you start playing around with the compression. The higher the compression the colder the plug you need to prevent ping.
I have very high compression. I use a NGK BR9HIX Iridium plug. There are reasons to use a Rare Earth plug, I won't go into them here but for your motor a BPR5HIX is what I'd recommended as far as a iridium plug would go.