Re: Im going to run a NGK B5HS spark plug....
i've been running a 7, just because i was always hammering around at top speed all summer, i wanted a colder range.
it still works fine now that it's colder (65 degrees, brrrrr,) but i might go to a 6. but i might not. depends on if my bike starts acting up.
as far as the stock plug goes, the extra one i got with my kit was cracked, probably from rolling around in the box. it was a hairline crack, and if i was new to all this, and didn't know what a spark plug was, i woulda installed it.
then i'd be on here asking "does anyone else have a two-piece spark plug?"