Just joined, just bought a used 07 s40, 4k miles,.....no mods,...stock as a clock as far as I know. It runs good in general. But I notice when under light throttle conditions, if I pull the choke out a notch, it will pick up a little speed, and runs a touch smoother. Is this kinda normal, or or should something be enriched a little? It idles very good, so can I assume that the screw adj under the brass plug is ok ? Mite a little trim of the spacer fix this ? I love the bike, and it is ok even if nothing was ever changed, but wondered about the seemingly lean condition.
Thanks for any reply.

Rich

check out the carbs, jetting, and exhaust section under the table of contents in the tec section.  everything you need to know.